A histochemical study of aldehyde fuchsin‐positive material and “high‐esterase cells” in the pineal gland of the Mongolian gerbil

Abstract

The pineal gland of the Mongolian gerbil consists of a superficial gland, stalk and deep pineal. The deep pineal differentiates postnatally. Histochemical studies of the superficial pineal gland indicate that it may be involved in the secretion of protein. Presumptive secretory material visualized by aldehyde fuchsin (AF) and chrome hematoxylin was observed along the course of blood vessels and among the pinealocytes. The distribution and texture of the AF-positive material was distinctive. It did not correspond to the pattern and texture of material stained with PAS, Sudan Black or acid orcein. Staining with AF was markedly reduced after incubation with trypsin, indicating that the AF-positive material is at least partially protein. The amount of stainable material increased with age. The AF-positive material was observed in what appeared to be interstitial or glial cells and processes, and in the processes of perivascular cells. Cells and fibrous processes with high non-specific esterase activity ("high-esterase cells") were observed among the pinealocytes and along the course of blood vessels. The distribution of the "high-esterase cells" and the morphology and texture of their esterase-containing processes were remarkably similar to the morphology and distribution of the material that stained with AF. It may be that the "high-esterase cells" contain AF-positive material. The "high-esterase cells" hydrolyzed both alpha-naphthyl acetate and alpha-naphthyl butyrate. The pinealocytes hydrolyzed only alpha-naphthyl acetate. The "high-esterase cells" appear to form a distinct class of cells within the superficial pineal gland. They are tentatively identified as a type of glial cell.

Modes of protein and peptide uptake in the pineal gland of the Mongolian gerbil: An ultrastructural study

“…This route could provide a means for secretion by the pineal gland into the CSF. Adeep pineal gland has only been reported in a few species including the gerbil (Japha et al, 1977) and the hamster (Sheridan and Reiter, 1970). The functional significance of the deep pineal gland is still to be elucidated.…”

CSF‐contacting pinealocytes in the pineal recess of the Mongolian gerbil: A correlative scanning and transmission electron microscope study

“…The Mongolian gerbil possesses both a superficial and a deep pineal gland (Japha et al, 1977), with the latter located in close apposition to the third ventricle. Recently, Hewing (1982) demonstrated the presence of CSF-contacting pinealocytes in the suprapineal recess of the gerbil.…”

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

“…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],…”