On the presence of different populations of pinealocytes in the mammalian pineal gland

Abstract

The different categories of cells described by many authors in the pineal gland of mammals have been critically considered. In some mammalian species, two different populations of pinealocytes have been observed. To each of these populations a specific secretory process can be attributed. One is characterized by the formation of granular vesicles originating from the Golgi apparatus, the other by the formation of material directly from the cisterns of the granular endoplasmic reticulum. Both of these secretory processes appear to be also present in the pineal of the mole, the hedgehog, and the rat, mammals in which generally only one population of pinealocytes has been described. The physiological consequences of these findings have been discussed.

A Light and Electron Microscopic Study of the Pineal Body of the Nutria (<i>Myocastor Coypus</i>)

“…These terms have created much con fusion in the literature [Pevet, 1977], Fur thermore, it has yet to be resolved whether these staining differences represent fixation artifacts [Pevet, 1974;Welsh and Reiter, 1978] or expressions of different functional states in a single line of pinealocytes [Sheri dan and Reiter, 1973;Pevet, 1974;Mat sushima and Reiter, 1975a]. The present study cannot resolve this question.…”

The proteinaceous content and possible physiological significance of dense-cored vesicles in hamster and mouse pinealocytes

“…In studies on laboratory rats or wild mammals, Pevet (1977a), Pevet and Karasek (1977), Karasek and Marek (1978) considered two types of secretory processes in pinealocytes. One was first proposed by Vivien (1964) in the ringed-snake, then generalized to other Amniota by Collin (1969Collin ( , 1979 On the basis of ultracytochemical, cytophysiological and biochemical data, Collin (1969Collin ( -1979 (Pevet and Karasek, 1977 ; Karasek and Marek, 1978).…”

“…One was first proposed by Vivien (1964) in the ringed-snake, then generalized to other Amniota by Collin (1969Collin ( , 1979 On the basis of ultracytochemical, cytophysiological and biochemical data, Collin (1969Collin ( -1979 (Pevet and Karasek, 1977 ; Karasek and Marek, 1978). However, it must also be noted that the material originating directly from the cisternae of the rough endoplasmic reticulum is not specific to pinealocytes, the chief cells of the pineal gland (Collin, 1979 (Pevet, 1977a) and more recently in the receptor cells of pike (Falcon, unpublished data).…”

Influence of hypophysectomy and prolactin on the rat pinealocyte : a quantitative ultrastructural study

“…At least two types of secretory processes are reported to be present in mammalian pinealocytes (Pevet, 1977 ;Pevet and Karasek, 1977). The first process (neurosecretory-like) is characterized by the formation of DCV by the Golgi apparatus, while the second process (ependymal-like) is characterized by a peculiar activity in the granular endoplasmic reticulum.…”