“It seems as if we’ve been made to fear the sun resulting in adults & kids being drenched in a bath of toxic hormone-disrupting chemicals.” (http://collective-evolution.com); 6 SCARY SUNSCREEN INGREDIENTS

 

Oxybenzone This penetration enhancer (i.e., chemical that helps other chemicals penetrate the skin) undergoes a chemical reaction when exposed to UV rays. When oxybenzone is absorbed by your skin, it can cause an eczema-like allergic reaction that can spread beyond the exposed area and last long after you’re out of the sun. Experts also suspect that oxybenzone disrupts hormones (i.e., mimics, blocks, and alters hormone levels) which can throw off your endocrine system. According to the Centers for Disease Control and Prevention (CDC), 97 percent of Americans have this chemical circulating in our bodies, as it can accumulate more quickly than our bodies can get rid of it.

Octinoxate One of the most common ingredients found in sunscreens with SPF, octinoxate is readily absorbed by our skin and helps other ingredients to be absorbed more readily. While allergic reactions from octinoxate aren’t common, hormone disruption is: the chemical’s effects on estrogen can be harmful for humans and wildlife, too, should they come into contact with the chemical once it gets into water. Though SPF products are designed to protect skin from sun-induced aging, octinoxate may actually be a culprit for premature aging, as it produces menacing free radicals that can damage skin and cells.

Retinyl Palmitate (Vitamin A Palmitate) Just like the vitamin A we eat, retinyl palmitate is an antioxidant. As an ingredient in sunscreen, it’s function is to improve the product’s performance against the aging effects of UV exposure, However, certain forms of vitamin A found in sun protection products—namely retinyl palmitate, a combination of retinol (vitamin A) and palmitic acid, an ingredient found in tropical plants such as palm and coconut—can be cause for concern. When exposed to the sun’s UV rays, retinol compounds break down and produce destructive free radicals that are toxic to cells, damage DNA, and may lead to cancer. In fact, FDA studies have shown that retinyl palimitate may speed the development of malignant cells and skin tumors when applied to skin before sun exposure, so steer clear of skin sun products that harbor the stuff.

Homosalate This UV-absorbing sunscreen ingredient helps sunscreento penetrate your skin. Once the ingredient has been absorbed, homosalate accumulates in our bodies faster than we can get rid of it, becomes toxic and disrupts our hormones.

Octocrylene When this chemical is exposed to UV light, it absorbs the rays and produces oxygen radicals that can damage cells and cause mutations. It is readily absorbed by your skin and may accumulate within your body in measurable amounts. Plus, it can be toxic to the environment.

Paraben Preservatives Associated with both acute and chronic side effects, parabens (butyl-, ethyl-, methyl-, and propyl-) can induce allergic reactions, hormone disruption, developmental and reproductive toxicity. While butylparaben was reported to be non-carcinogenic in rats and mice, but it has been previously suspected that parabens and other chemicals in underarm cosmetics may contribute to the rising incidence of breast cancer.

THE EXTRACTION OF MELANIN FROM SKIN WITH DILUTE ALKALI. BY WILLIAM JOHN YOUNG.

BY WILLIAM JOHN YOUNG.
The Australian Institute of Tropical Medicine,
Townsville, N. Queensland.
(Received December 23rd, 1920.)
IT has generally been assumed that the black pigments (melanins) which occur normally or pathologically in animal tissues, hair, skin, feathers, etc. are chemically very inert substances, and in most cases their isolation has been carried out by dissolving the tissue in boiling alkalies or strong acids. Thus Abel and Davis [1896] prepared melanins from both the skin and hair of a negro by heating the material at 1000 either with 5-6 % potassium hydroxide or witb concentrated hydrochloric acid until all the keratin had dissolved.

Other investigators have used even more drastic methods such as boiling with more concentrated alkalies or even fuming hydrochloric acid. That some melanins are really not so resistant to alkalies and acids was shown by Gortner [1910] who investigated the effects of alkalies upon the melanin of black-sheep’s wool. He extracted the pigment from the wool by boiling with successive portions of a 0-2 % solution of sodium hydroxide, and  from the first two or three extracts he obtained a melanin of constant composition, C= 52-57 %, H= 7.28 %, N = 13.43 %, S = 1-33 %. This substance when purified contained no ash, was soluble in alkali and in very dilute mineral acids (N/20), and was precipitated by stronger acids. After boilingthis with stronger alkali a pigment could be precipitated by acid from the solution, which contained less nitrogen and hydrogen than the original, and was no longer soluble in dilute acids.
This acid-soluble pigment was only obtained from the first two or three extractions, the subsequent extracts yielding a different pigment, insoluble in acid and containing less nitrogen and hydrogen, and Gortner considered this to be a decomposition product of the acid-soluble pigment. When stronger solutions of alkali were employed for the extraction, the compounds obtained were insoluble in acid, and their nitrogen and hydrogen decreased, in general, as the concentration of alkali increased; thus the substance extracted with 50 % sodium hydroxide contained only 3*84 % hydrogen and 8-98 % nitroget.

MELANIN FROM SKIN

So far from being inert to alkalies the melanin of sheep’s wool was thus readily decomposed by boiling with sodium hydroxide in concentrations over 0-2 %, whilst even this concentration decomposed the pigment on continued boiling.
From these results Gortner considered that in all probability many of the melanins described in the literature were really products of the decomposition of melanin and not the pigment as it occurs in the natural material. The melanin obtained by Abel and Davis from negro skin was left in the form of pigment “granules” (pigment and pigment structure) after the keratin had dissolved in the alkali; and the pigment was freed from the pigment structure by continued treatment with 5 % hydrochloric acid, and subsequent extraction with potassium hydroxide. It then had the composition C = 53.56 %, H= 5*11 %, N= 15.47 %, S = 2-53 %. The author [Young, 1916] described the preparation of a melanin from
the skin of an Australian aboriginal, by treatment with successive portions of boiling 5 % sodium hydroxide, each portion being allowed to act for a short time only. In this preparation no granules were obtained but the pigment was gradually dissolved in the alkali, from which it was obtained by precipitating with acid. The analysis differed from that of the preparation of Abel and Davis as it gave C – 60-12 %, H = 6-70 %, N = 11-89 %. More recently an opportunity of obtaining more material came to hand,  and further preparations were made, the method being modified so that a more dilute alkali (N/20) could be employed in the extraction. Pigments were extracted with this alkali from portions of the skin from two Australian aboriginals and a low caste Cingalee.

Preparation.
It was found that if the skin were soaked in boiling water, the outer layer, which contained practically all the pigment, could be readily removed by scraping. This layer (200 g.) was washed with alcohol and ether to remove grease, and was boiled with 100 cc. of N/20 sodium hydroxide for one hour under a reflux condenser. It was allowed to settle and the dark liquid decanted and filtered. The process was repeated with successive portions of fresh alkali until, after four extractions, there was only a very small residue. To the four clear filtrates after cooling, hydroehloric acid was added to about N/3, whereby the melanin was thrown down as a dark-brown precipitate. It was allowed to settle, the liquid siphoned off and the precipitate repeatedly washed by decantation with N/3 hydrochloric acid. The clear washings were siphoned off as much as possible and water and hydrochloric acid added to make the liquid to 500 cc. of N/20 hydrochloric acid. The mixture was then heated to boiling. The precipitates from the first two extracts completely dissolved to a deep brown solution; that from the third extract was only
partially soluble; whilst the fourth precipitate did not appear to dissolve at all. The solutions were filtered through a fine filter paper (Schleicher and 119 W. J. YOUNG Schuill’s Blue Band), and the first three solutions mixed. In this way the pigment was separated into two fractions, one soluble, the other insoluble in dilute hydrochloric acid. The solution in hydrochloric acid was cooled, and concentrated acid added until the mixture was N/3. The melanin was thereby precipitated and was allowed to settle, the liquid siphoned off, and the residue washed several times by decantation with hydrochloric acid of the same strength. The process of dissolving in N/20 acid, filtering and-reprecipitating  was repeated once, the pigment was then again dissolved in the dilute hydrochloric acid, and the solution dialysed until the liquid no longer gave a precipitate with silver nitrate. This treatment precipitated the pigment, which was then filtered off on  a hardened paper, washed with distilled water, then with alcohol, finally with ether and dried. The paper was folded and extracted in a Soxhlet apparatus, successively with carbon disulphide, light petroleum and ether, and was dried at 1000. It was thus obtained as a black powder, and will be referred to as acid-soluble melanin. Before being dried the powder was readily soluble in dilute (N/20) sodium hydroxide, and in glacial acetic and concentrated sulphuric acids. It dissolved on warming in dilute (N/20) hydrochloric and acetic acids. After drying at 1000 it dissolved only with difficulty in boiling dilute alkali, more readily in stronger alkali, and was almost insoluble in
dilute hydrochloric acid. The pigment from the later extractions of the skin, which was insoluble
in dilute acid, was also purified by treatment on the filter paper repeatedly with boiling N/20 hydrochloric acid. It was then washed repeatedly with water and subsequently dissolved in warm N/20 sodium hydroxide. The melanin was precipitated by adding hydrochloric acid in slight excess, washed
by decantation until free from acid, filtered and washed with alcohol and ether, and extracted as before with carbon disulphide, light petroleum and ether, and dried at 1000. This powder, after drying, dissolved completely, but only very slowly, in boiling alkalies. In the above manner both acid-soluble and acid-insoluble preparations were obtained from the three skins.  Analysis of products. The carbon and hydrogen were determined by burning in a current of oxygen by Dennstedt’s method, lead peroxide being employed to keep back any oxides of nitrogen and sulphur. The yields of material were too small
for a separate estimation of sulphur, and in some cases the sulphur was therefore estimated at the same time by Dennstedt’s method. The quantity of barium sulphate actually weighed was very small, so that the results must only be  regarded as approximate. Nitrogen was estimated by Kjeldahl, the heating
with sulphuric acid being continued for four hours after the solution had become clear, as recommended by Dakin and Dudley with pyrrole compounds. 120
MELANIN FROM SKIN
In one preparation nitrogen was estimated both by Kjeldahl’s and by Dumas’ methods with practically identical results. In all cases before analysis the material was dried to constancy in vacuoat 100° over phosphorus pentoxide. In some preparations which contained a high percentage of ash samples were again treated by suspending in N/3 hydrochloric acid in a dialyser, allowing the acid to dialyse away, and washing and drying as before, whereby  the ash was very considerably reduced. In such cases the analysis before and after this treatment is given. The percentages are all calculated for the ashfree
substances and the results are tabulated below. Sol. in di]. acid Insol. in dil. acid C H N S Ash C H N S Ash I. Aust.

Black I:
(a) … 56-41 7-33 – – 7-02 56-03 5-86 – – 3-51
(b) After further treatment
to remove inorg. matter 56-33 7-37 12-46 – 2-78 55-92 6-25 1-77 2-60
II. Aust. Black II:
(a) Extracted by first portion
of alkali … 55-49 8-30 13-54 – 0-67
(11-95′ 59-87 7-27 10-80 1-66 1-39 (b) Extracted subsequently 56-81 6-68 12:24 2-49 4-03
III. Cingalee:
(a) … 56-01 6-24 – – 5.47
(b) Afterfurthertreatment 56-06 6-71 14-57 2-56 2-68 56-06 6-58 13-27 2-37 3-09
Previously found with 5 %
alkali … … 60-10 6-70 11-89 – –

 

In all cases the ash was left as a light brownish powder, only partially soluble in hot hydrochloric acid, and containing a small amount of silica. Estimations of the iron in the ash were made colorimetrically with potassium thiocyanate, and the quantity was found to vary from nothing in one sample, to 7 % of the total ash in another, the latter quantity corresponding to 0-2 % of the original pigment. The iron was therefore not an essential part of the melanin molecule. The ash also contained a trace of sulphate. From the foregoing analyses it is seen that the ash was materially reduced by treatment of the melanin with acid, without altering the carbon and hydrogen percentage calculated on the ash-free substance. It would appear, therefore, that the ash is not an essential part of the melanin. Action of alkali on the acid-soluble melanin. A small quantity (about 0-5 g.) of the acid-soluble pigment from the Cingalee skin was boiled with N/20 alkali in a reflux apparatus. The sample which had been previously dried at 1000 dissolved only slowly, passing, however, completely into solution after about five hours’ boiling. The boiling
was continued for 15 hours, after which the mixture was cooled, exactly 121 neutralised with N hydrochloric acid, and sufficient acid added to bring the whole to N/20. The melanin was partially precipitated, and even when heated to boiling some of the precipitate did not redissolve. That this was not due to the drying alone was shown by warming another portion of the original dried melanin with the alkali until solution had taken place, neutralising and making to N/10 hydrochloric acid and boiling. In this case the melanin completely dissolved. The pigment soluble in acid behaved, therefore, like Gortner’s pigment, in that it was altered slowly by continued boiling with dilute alkali into a
substance no longer soluble in dilute acid. Sufficient material was not available to test whether nitrogen and hydrogen were lost during this treatment.

DISCUSSION OF RESULTS.
It will be seen from the table of results that variations were found in the percentage composition of the different preparations. The acid-soluble pigment generally contained a lower carbon percentage and a greater percentage of nitrogen and hydrogen than the acid-insoluble pigment subsequently extracted from the same skin, although the insoluble preparations from one skin did not always contain less nitrogen and hydrogen than soluble preparations from another. It is observed also that in the case where the first  extraction was kept separate the same difference was found between this and the pigment from subsequent extracts, although both pigments were soluble in acids. Continued boiling with dilute alkali converted the pigment soluble in acid to one insoluble in acid; it seems therefore probable that in extracting the pigment even with very dilute sodium hydroxide (N/20) it is gradually decomposed, losing nitrogen and hydrogen and gradually changing to a pigment insoluble in acid. The melanin of black skin thus resembles that prepared from wool by Gortner in that a pigment may be extracted with alkali which is soluble in dilute acids, and which, on further heating with alkali, changes to a pigment
insoluble in dilute acids, with loss of nitrogen and hydrogen. In this case, however, a constant product could not be obtained, and it is possible that none of the preparations represents the pigment as it occurs in the skin. The preparations gave quite different analyses from the pigment from negro skin prepared by Abel and Davis.

REFERENCES.
Abel and Davis (1896). J. Exp. Med. 1, 361.
Gortner (1910). J. Biol. Chern. 8, 341.
Young (1914). Biochem. J. 8, 460.

Melanin is worth $365 per gram

tf1b-m2l1n3n_w4rth

Whites attribute their failure of reproduction to behavioral or societal reasons. However, the reason is more a biological one. Melanin is present at the inception of life: A Melanin sheath covers both the sperm and the egg! In the human embryo, the melanocytes (skin pigment cells), brain and nerve cells all originate from the same place; the neural crest. Melanocytes resemble nerve cells and are essential for conveying energy. When Melanin is missing or insufficient in the ectoderm of the early embryo (blastula), this causes the mother to lose her baby; in the case of whites, a defective baby is produced, and over time, through inbreeding, wears down the already pathetically low levels of melanin. Reproduction stops altogether and virtual infertility is the end result.

As far as vitamin D metabolization, white people have the lowest bone density of all people on the planet probably because of the climate inhabited. Vitamin D is produced by sun exposure. The skin is supposed to convert sunlight to Vitamin D because of 7-Dehydrocholesterol. However, white people reflect the sunlight so that the body compensates by depleting calcium from their bones. It makes whites more susceptible to kidney stones than any other race of people. The depletion of bone mass is responsible for their low bone density. It is widely regarded that black people have the strongest bones of all people from infancy to old age.

Melanin has been proven to not only refine the human reproductive system and nervous system, but melanin also plays an important part in sight and hearing. Blue eyes are simply eyes that lack melanin. Blue eyes are more sensitive to sunlight and do not process light or produce sight as efficiently as brown eyes. Isn’t it funny how many people place divine qualities with blue eyes that are nothing but genetically defective?

Melanin is also said to be linked with hearing. Melanocytes are present in the inner ear, the eye, and in the membrane that covers the brain and spinal cord. It has been demonstrated that melanin deposits in these areas are proportional to the amount of melanin found in the skin. These areas of the body, similar to the skin, are exposed to high-energy free radicals that can damage the surrounding cells, and thus causes a lower threshold for hearing. Evidence shows that black people, on average, hear better than whites, and that within both races, women surpass men. A partial explanation of the differences may lie in the abundance in the inner ear of melanin pigments. Also, numerous studies have found that people with light eye colors, such as blue, green, and hazel are more vulnerable to hearing damage than are people with black or brown eyes.
Continue reading

Melanin Pigments in Human Pineal Gland (Journal of the Anatomical Society of India)

TF1B-dwdrl-Abstract

Masson-Fontana staining confirmed the presence of melanin pigments in the human adult pineal gland. In 1-10 years age group, the pigments were present within the pinealocytes. In 11-20 years age group also, the pigments were in the pinealocytes only. In 21-30 year age group, the pigments were in the pinealocytes and appeared in the stroma in the areas of glial fibre predominance. In 31-40 years age group onwards, the pigments were present, in addition to pinealocytes, in the stroma among the fibres. As age advanced, the amount of extracellular pigments gradually increased, extracellular pigments were more concentrated, and the extracellular pigments were more clearly seen. There was no gender difference in the amount of melanin pigments. The background comparative anatomy also is discussed.

Key words: melanocyte, melanin, pinealocytes, pineal gland

Introduction:

Melanocytes are melanin-pigment synthesizing pigment cells derived from neural crest and widely distributed in vertebrates. They are stellate cells with long processes with numerous dark brown or black granules of melanin in their cytoplasm. There function is generally, to prevent light from reaching adjacent cells. In humans, they are present in the epidermis and its appendages, oral epithelium, some mucous membranes, uveal tract of eye ball, parts of middle and internal ear, and parts of leptomeninges in the base of brain. The cells of retinal pigment epithelium, neurons in locus ceruleus and substantia nigra also synthesize melanin. Melanins are high molecular weight polymers, attached to a structural protein, to form melanoproteins, and in the humans, there are two classes, the brown-black eumelanin and red-yellow pheomelanin, both derived from a substrate tyrosine (Dyson 1995).

Pineal gland (epiphysis cerebri) was once considered to be a phylogenic relic, a vestige of a dorsal third eye, and of little functional significance; the mammalian pineal is now regarded and accepted as an endocrine gland of major regulatory importance, modifying the activity of the adenohypophysis, neurohypophysis, endocrine pancreas, parathyroids, adrenal cortex, adrenal medulla, and gonads. (de Vries and Kappers 1971; Klein 1978; Haulica and Coeulescu 1981; Reiter 1983, 1985, 1987; Malendowicz 1985; Dyson 1995).

The pineal in the big brown bat is pigmented and intensified with constant darkness (Bhatnagar and Hilton 1994). Pigmented cells in the cat pineal gland show a preferential localization at the ventral surface of the pineal gland near its distal end and the pineal pigment is melanin (Calvo et al. 1992). Presence of pigment cells is a constant characteristic in the adult dog pineal gland; the pigment is melanin (Calvo et al. 1988). Embryo ovine pineal gland has pigment cells containing melanin (Regodon et al. 1998). Pineal glands of neonates consist of cords of dark, nucleated cells, which are frequently pigmented (Min et al. 1987). In the human adult, melanin pigments gradually accumulate within the parenchymal cells with increasing age in males, whereas in females, the maximum pigmentation is noticed in 30-40 year age group and then there was a fall (Tapp and Huxley 1972). The present study was done to find whether or not the human adult pineal gland showed gender difference and age changes in the amount of melanin pigments.

Materials and Methods:

Forty pineal glands were collected from South Indian subjects (31 males and 9 females) who were accident deads, within five to six hours after death during autopsy. There were no histological postmortem changes. Age of the subjects ranged from one to eighty years. Age groups of the subjects were 1-10, 11-20, 21-30, 31-40, 41-50, 5160, 61-70, 71-80 years.

Pineal glands were removed from the brain along with the superior colliculus so that the pineal recess of the third ventricle was also included. These were put in Bouin’s fluid. After fixation, the specimens were processed for light microscopy. Eight-micron serial sections were cut and stained. Staining methods used were (i) haematoxylin and eosin, (ii) Masson-Fontana method for melanin, and (iii) Mallory’s phosphotungstic acid haematoxylin method for neuroglial cells and nerve fibres. The arrangement of the parenchyma and stroma was observed. Melanin pigments were visually studied for location and quantity with regard to gender and age.

Observations:

Pineal gland had a well defined capsule (piamater) and septa extended from the capsule into the parenchyma dividing it into complete and incomplete lobules. Parenchyma consisted of light and dark pinealocytes and glial cells. Corpora arenacea were a constant feature (Koshy and Vettivel 2001). Melanin pigments were present in the pinealocytes and in the stroma. In 1-10 years age group, the parenchyma was highly cellular, predominantly of pinealocytes. Within the pinealocytes, melanin pigments were present. There were no extra cellular pigments. In 11-20 years age group, the parenchyma was highly cellular with the presence of pinealocytes. Pigments were present as in 1-10 year group, within the pinealocytes. In 21-30 years age group, abundant dark melanin pigments were inside the pinealocytes and in the areas of glial fibre predominance. The pinealocytes were not abundant as in 11-20 age group but extracellular pigments were in the transition areas from pinealocytes-predominance to glial fibre-predominance (Fig. 1). In pineal glands of higher age groups, 31-40, 41-50, 51-60, 61-70 years, melanin pigments were seen as clear granules, more among the fibres. The pinealocytes also had melanin pigments within them. The extra cellular pigments were more clearly seen as age advanced. There was no gender difference in the amount of melanin pigments. A gradual increase in melanin, more concentrated extracellularly, occured as age advanced.

Discussion:

Pineal gland projects from the roof of diencephalon. A recess of third ventricle extends into its stalk. The pineal was formerly considered a vestigial organ with no function but now it is known to be an active endocrine gland. Its activity is influenced by the daily cycle of light and dark and it is a link between environment and physiology of an organism (individual). It responds to annual changes in day-length and influences gonadal activity in seasonal breading species but has, though less apparent, significant effect on the reproductive system of other species that breed throughout the year. Its innervation is exclusively via sympathetic fibres that originate in the superior cervical ganglion and enter the cranial cavity accompanying blood vessels supplying the brain (Fawcet 1994).

Paired eyes of vertebrates are organs to focus a clear image upon a film of sensory cells known as retina, and these cells convey the impulses to the brain, giving their interpretation of intensity, colour, or movements. In some primitive vertebrates, there are also two different median organs, which serve as receptors for light, although not necessarily to obtain visual images. There are indications, from elasmobranch embryology, that the prevertebrates possess a metameric series of paired visual organs on the roof of the head; most of them rapidly disappear as the lateral eyes become perfect; but two pairs of dorsal eyes still hang on, almost to the cyclostome level. In lamprey, one member of each of these supposed pairs might be seen as a small bulb, attached by a stalk, to the root of the diencephalon. The anterior one (parietal stalk) does not quite reach, but the posterior (pineal eye) does reach a semitransparent spot in the skin of the head. Possibly, both bodies were present in primitive amphibian, for in frogs, the pineal is found, nearly reaching the skin; yet in some modern reptiles (sphenodon and lizards) a parietal eye is present, with the pineal redued. Among early vertebrates, the evidence of these organs is simply a foramen in the roof of the skull in ostracoderms, some placoderms, crossopterygians, primitive amphibians, and some of the early reptiles, including Therapsids. It usually lies between the parietal bones. The parietal eye of the Sphenodon is well covered, and no function has been demonstrated, but it contains a retina and a lens; the neurosensory retinal cells synapse with neurons, which go directly down the stalk. In birds, the pineal stalk is reduced but often distinct and with a complicated structure distally. Mammals have a minute epiphysis (pineal organ), which has been suspected to have an endocrine function (Eaton 1960).

In most fish, and amphibians, the pineal organ is a single sac. In the more primitive fish, tail-less amphibians and lizards, there is a second component, the parapineal organ or parietal organ, which arises as an anterior evagination of the pineal organ or as a separate outgrowth of the roof of diencephalon. In frogs, parapineal component lies just beneath the epidermis on the dorsum of the head, where it can be seen. Numerous nerves and nerve endings are found in the pineal organs of lower vertebrates. Pineal organs of lower vertebrates reveal presence of photoreceptor cells that resemble those of the mammalian retina in having a lamellar portion of the apex and a receptor synapse at the base. The most elaborate pineal is found in the primitive lizard, Sphenodon. It contains a simple retina, consisting of photoreceptors backed by supporting cells that contain pigment, and its parietal component includes a lens-like structure. It thus constitutes a vestigial parietal eye. Probably, the parietal eye of the Sphenodon was functional because of the large size of the pineal foramen in the fossil reptiles (Fawcett 1994).

Pineal gland contains cords and follicles of pinealocytes and neuroglial cells among which ramify blood vessels and nerves. Pinealocytes form the pineal parenchyma; neuroglial cells, partially separating the pinealocytes, are like astrocytes. Ultrastructure of human fetal pinealocytes indicates their secretory function in early intrauterine life (Moller 1974). As in adults, they contain all the appropriate organelles together with abundant microfilaments, microtubules, and a few cilia with a 9 + 0 microtubular pattern. Cilia of this type are associated with secretory cells in other endocrine glands (Barnes 1961; Andersen et al. 1970). Extending from the cell body are one or more processes (Knight et al 1973), which end in terminal buds near blood vessels or ependymal cells of the pineal recess. The terminal buds contain electron dense cored vesicles, which store monoamines and polypeptide hormones (Sheridan and Sladek 1975), release of which requires sympathetic innervation. The polypeptide hormones combine with specific protein carriers, termed neuro-epiphysins (Lukaszyk and Reiter 1975). They are released by exocytosis together with exocytotic debris. When released, the complex dissociates, hormones being exchanged for calcium ions. The calcium-carrier complex so formed is, in the pineal, deposited concentrically around exocytotic debris as corpora arenacea or brain sand. It is often supposed that the pineal gland atrophies with age, corpora arenacea being a sign of atrophy; on the contrary, these corpuscles may indicate continued secretion. There was no evidence of pineal degeneration in the elderly (Wildi and Frauchiger 1965).

The pinealocytes of mammals evolved from the photoreceptor cells of the pineal organ of primitive vertebrates. In the course of their evolution from light sensitive elements to endocrine cells, the region of the cell, specialised for photoreception was lost, together with the sensory nerves connecting it to other regions of the brain. The synaptic ribbons of mammalian pinealocytes may be vestiges of the special synapses that are characteristic of photoreceptors. Whether they have acquired an alternate function, related to secretion, is not known (Fawcett 1994). Pinealocytes of some mammals contain synaptic ribbons, perhaps involved in transmission; vesicles near them contain neurotransmitters such as – aminobutyric acid (Krstic 1976). Similar arrangements of organelles occur in mammalian retinal photoreceptors and simpler submammalian photoreceptors, suggesting that mammalian pinealocytes are derived from photoreceptors (Kappers 1976; Relkin 1976). Transient similarities exist between pinealocytes and retinal photoreceptors in neonatal rats (Zimmerman and Tsi 1975).

Melanin pigments are associated with light and are found in association with photoreceptors. This association, probably, exists with photoreceptor cells-derived pinealocytes also. It is possible that the pigments, corresponding to those (rodopsin) in photoreceptors and those in the supporting cells in Sphenodon pineal gland, are in the pinealocytes and stroma in the human pineal gland. Increase of melanin pigments is due to the action of pineal indole-melatonin. Melatonin suppresses the melanocyte-stimulating hormone and prevents dispersion of melanin granules. Therefore, the melanin pigments become concentrated in the pineal gland.

The sphenodon pineal has pigments in the supporting cells of the photoreceptors. Mammalian retina has pigment cell layer. Melanin pigments have been shown to be present in animal and human fetal pinealocytes. Correspondingly, the present study, light microscopically, has shown melanin pigments in the human adults. Melanin pigments gradually accumulate within the parenchymal cells with increasing age in males, whereas in females, the maximum pigmentation is noticed in 30-40 year age group and then there is a fall (Tapp and Huxley 1972). The present study shows that there is no gender difference in the amount of melanin pigments, that a gradual increase in melanin pigments, more concentrated extra cellularly, occurs and that melanin pigments are more clearly seen as age advances.

Acknowledgement:

The help of Dr. Valsamma Mathew, Department of Anatomy and Dr. Radha Krishnan, Department of Forensic Medicine of Kottayam Medical College, Kottayam is acknowledged.

References:

  1. Anderson, H., Bulow, F.A. Von, and Mollgard, K. (1970): The histochemical and ultrastructural bases of the cellular function of the human fetal adenohypophysis. Prog Histochem Cytochem 1 : pp 153-184.
  2. Barnes, B.G. (1861) Ciliated secretory cells in the pars distalis of the mouse hypophysis Journal of Ultrastructural Research 5 : pp 453-467.
  3. Bhatnagar, K.P. and Hilton, F.K. (1994) : Observations on the pineal gland of the big brown bat, Eptesicus fucus : possible cerrelation of melanin intensification with constant darkness Anatomical Record 240 : pp 367-376.
  4. Calvo, J.L., Boya, J., Garcia-Maurinao, J.E. and Lopez- Carbonell A. (1988) : Structure and ultrastructure of the pigmented cells in the adult dog pineal gland. Journal of Anatomy 160 : pp 67-73.
  5. Calvo, J.L. Boya, J., Garccia-Maurino, J.E. and Rancano, D. (1992): Presence of melanin in the cat pineal gland. Acta Antaomica (Basel) 145 : pp 73-78.
  6. De Vries, R.A.C. and Kappers, J.A. (1971) : Influence of the pineal gland on the neurosecretory activity of the supraoptic hypothalamic nucleus in the male cat. Neuroendocrinology 8: pp 359-366.
  7. Dyson, M. Gray’s Anatomy. In : Endocrine system. 38th Edn Churchill Livingston, London. pp. 1888-1891. (1995)
  8. Eaton, T.H. Jr.: Comparative Anatomy of the Vertebrates. 2nd Editon. Harper & Row, New York. pp. 299-300 (1960)
  9. Fawcett, D.W. Text Book of Histology. 12th Editon. Chapman & Hall, New York pp. 516-523 (1994)
  10. Haulica, I, and Coculescu, M. (1981) : Is agnitensin a new pineal hormone ? Rev Roum Medical Endocrinology 19 : 3-21
  11. Kappers, J.A. (1976): The Mammalian pineal gland. A survey. Acta Neurochirology Genessks 120 pp 109-149.
  12. Koshy, S. and Vettivel, S. (2001) : Varying appearance of calcification in human pineal gland. A light microscopic study Journal of Anatomial Society of India. 50(1): pp 17-18.
  13. Klein, D.C. (1978) : The pineal gland : a model of neuroendocrine regulation. Research Publishers Association Research on Nervous & Mental Disease 56 : pp 303-327.
  14. Knight, B.K., Hayes, M.M.M. and Symington, R.B. (1973) : The pineal gland – a synopsis of present knowledge with particular emphasis on its possible role in control of gonadotrophin function. South African Journal of Animal Sciences 3: 143-146.
  15. Krstic, R. (1976) : Ultracytochemistry of the synaptic ribbons in the rat pineal organ. Cell Tissue Research 166 : pp. 135143
  16. Lukaszyk, A. and Reiter, R.J. (1975): Histophysiological evidence for the secretion of polypeptides by the pineal gland. American Journel of Anatomy. 143 : pp 451-464.
  17. Min, K.W., Seo, I.S. and Song J. (1987): Postnatal evolution of the human pineal gland. An immunohistochemical study. Laboratory Investigation 57 724-728.
  18. Moller, M, (1974): The ultrastructure of the human fetal pineal gland. I. Cell types and blood vessels. Cell Tissue Research 152: pp 13-30.
  19. Regodon, S., Franco, A.J., Gazquez, A. and Redondo E. (1998): Presence of pigment in the ovine pineal gland during embryonic development. Histology Histopathology 13 : pp 147-154.
  20. Reiter, R.J. (1983): The Pineal gland : an intermediary between the environment and the endocrine system Psychoneuroendocrinology. 8 : pp. 31-40.
  21. Reiter, R.J. (1985 a): Action Spectra, dose response relationships, and temporal aspects of light’s effects on the pineal gland. Annals N. York Academy of Sciences 453 : pp. 215-230.
  22. Reiter, R.J. (1985b): Impact of Photoperiodic information on pineal metabolism and physiology. International Journal of Biometereology. 29: pp 178-187.
  23. Reiter, R.J. (1987): The melatonin message : duration versus coincidence hypotheses. Life Sciences 40 : pp 21192131.
  24. Relkin, R. The pineal. Annual Reserch Review. Eaden Press Montreal, (1976)
  25. Sheridan, M.N. and Sladek, J.R., Jr. (1975): Histofluorescence and ultrastructural analysis of hamster and monkey pineal gland. Cell Tissue Research 164 : pp 145 152.
  26. Tapp, E. and Huxley, M., (1972): The histological appearance of the human pineal gland from puberty to old age. Journal of Pathology. 108: p 137-144.
  27. Wildi, E, and Frauchiger, E. (1965): Modification histologiques de Pepiphyse humaine pendent I’enfance, I’age adulte et le viellissement. Progr. Brain Research. 10 : pp 218-233.
  28. Zimmerman, B.L. and Psi, M.O.M. (1975): Morphological evidence of photoreceptor differentiation of pinealocytes in the neonatal rat. Journal of Cell Biology. 66 : pp. 60-75.

J. Anat. Soc. India 50(2) 122-126 (2001)

Missing Image

Thousands of Filthy Skinned US Devils Dare to Defy Sun of God’s Damnation of Caucasian Race saying, “we will Outrun the Sun!”

 Outrun the Sun Video 2013 Outrun the Sun Race Against Melanoma-Indianapolis Photo Gallery 2011 Photo Gallery 2010 Photo Gallery 2009 Photo Gallery 2008 Photo Gallery 2008 Outun the Sun Race Against Melanoma-Indianapolis Video Outrun the Sun is the official sun safety partner of Road Runners Club of America, Girls on the Run International and Youth Runner Magazine.