Ultrastructural and X-ray microprobe comparison of gerbil and human pineal acervuli

Cytochemical Analysis of Calcium Distribution in the Superficial Pineal Gland of the Mongolian Gerbil

“…The presence of both the fibriilar material [Krstic and Golaz, 1977;Welsh and Reiter, 1978;Allen et al, 19811 and the amorphous substance [Welsh and Reiter, 19781 has been previously described in association with the periphery of the PC. Employing scanning electron microscopy, Krstic [1976] described the presence of round 125-500 A particles on the surface of the concretions that were not influenced by either EDTA decalcification or trypsin treatment.…”

“…The PC are absent at birth and increase in number progressively with age Uapha et al, 1976;Zimmerman and Bilaniuk, 19821. X-ray microanalysis has revealed the presence of calcium and phosphorus as the main elements of PC [Krstic and Golaz, 1977;Allen et al, 19811. The mineral phase of the PC has been described as hydroxyayatite UT carbonate apatite [Angervall et aI., 1958;Earle, 19651.…”

Does a Centralized Clock for Ageing Exist?

“…( (2) Surface layer: To our knowledge, there are few modern ultrafine structural results concerning the outer layer of the pineal con cretions [ 15], On the other hand, apatites are among the most variable of chemical sub stances and crystals [16]. It may be signifi cant that iron appears only in the outer layer, as a marker perhaps, of human pineal con cretions [17].…”

Decreased Melatonin Biosynthesis, Calcium Flux, Pineal Gland Calcification and Aging: A Hypothetical Framework

“…With regard to the first theory, there is an organic moiety of acid, neutral and sulfated mucopolysaccharides, which are com ponents of the ground substance. As to the second, indole-rich proteins were detected [27], The inorganic moiety consisted of cal cium hydroxyapatite and calcium carbonate with minute amounts of strontium and mag nesium [28][29][30], Efforts to find one predominant cell type (fibroblast, arachnoid cell) responsible for the deposition of collagen and calcium have proved fruitless [31][32][33][34][35][36], Descriptive data suggested a stroma-parenchyma interaction [37][38][39][40] in which glial elements and protein play a negligible role [41].…”

“…Vacuolization associated with tryptophan-containing proteins and car rier protein for pineal hormones [67,68] gives pinealocytes a 'light' aspect [69], Several pieces of evidence indicate that the stage of vacuolar transformation (light pinealocyte) is of particular importance for the con sideration of intracellular calcium deposition. There is an increase in number and volume as well as accumulation of secretory vacuoles accompanied by intracellular calcium that oc curs during numerous endocrine shifts ob served in nature: the phase ushering in hiber nation and anestrus in the dormouse [70,71], the pre-estrous phase of the mole [68] and at the beginning of heat or sexual quiescence in the hedgehog [72][73][74] and the gerbil [30,61,75], Moreover in the gerbil, the number of vacuolated pinealocytes increases with the amount of calcification and with age [63], In humans, it seems plausible that day-night onoff switching has consequences on calcium transport and deposition similar to those re lated to seasonal reproductive cycles. This idea is supported by the finding that the histo genesis and composition of pineal calcifica tion in humans are histochemically and mor phologically identical to those of gerbils [30,61,75],…”