HISTOLOGICAL STUDY OF THE ANTERIOR PITUITARY IN RABBITS DURING THE HEALING OF EXPERIMENTAL BONE FRACTURE / 解剖学报

ABSTRACT

A segment of the diaphysis was sawed off from both radii of 57 adult male rabbits under anesthetic and antiseptic conditions.During healing of the bone,the pituitary bodies of these animals and 10 normal controls were removed and fixed in formol- HgCl_2 solution.Serial horizontal sections were prepared and stained with Adams' per- formic acid—Alcian blue—PAS (periodic acid—Schiff)—Orange G method for differentia- tion of the alpha-,S-,R-,and C-cells in the anterior lobe.The number of the 4 cell- types were counted under high power magnification.A total number of 2—3,000 cells in 6 fields selected from each gland were counted and classified and the percentage of each cell-type was calculated. Three days after the fracture,there is in the anterior pituitary,a significant increase in number of the scattered small-type S-cells (7.20?0.86% to 17.85?0.78%) and their cytoplasm shows an increase in stainability and an accumulation of granules,while the large-type S-cells in the anterior region show a decrease in number and loss of granules and stainability.In the light of the current results,the diffused small-type S-cells are probably concerned with the secretion of ACTH,and the large-type S-cells with the secretion of TSH. Two weeks after the fracture,the number of the alpha-cells increases (37.93? 1.83% to 57.44?4.15%) and their cytoplasm shows an increase of granules in- dicating that they are in a higher functional activity.This change seems to be related to the increased secretion of the STH during the latter period of healing of the bone fracture. The changes of R-cells and their significance await elucidation by further work.