“Glandular” Cells in the Pars Nervosa and Stalk of the Hypophysis

Abstract

This note summarizes the results of an investigation of the possible glandular nature of the parenchymatous cells of the pars nervosa of the hypophysis. Functional histological analysis in rats of various ages under experimental conditions leads to the conclusion that these cells produce and secrete anti-diuretic substance for the control of the water metabolism of the animal.

This “glandular” cell has been seen in the pars nervosa of almost every class of mammals, and of pigeons and chickens. The cell is distinguished by the presence of granules or of lipoid droplets which were first seen in fresh mounts. The inclusions fill the cytoplasm, and extend out into the cell processes. These intracellular elements are of approximately the same size in any one cell, though they may vary somewhat in size in adjacent cells. Histochemical analysis of the droplets or granules shows that in the rat they are rich in neutral unsaturated fats; no other lipoids have been identified. In some other animals, the granules contain no visible lipoids. The inclusions are preserved best by Maximow's fluid in the mouse and white rat.

The characteristic features of the glandular cell appear very early in the rat's embryonic life, being easily recognizable in a 23 mm. embryo. The number and size of the cells and of their inclusion bodies increase throughout life to become most prominent in rats 2 1/2 years old. The cells are distributed more or less evenly in the pars nervosa except at its junction with the hypophyseal stalk; there they are closer together. They are more widely separated and smaller in the remaining portion of the stalk than in the glandular portion.