A cytological study of the pars distalis of pituitary gland of normal, gonadectomized, and gonadectomized steroid hormone-treated green frog, Rana esculenta L

Abstract

The cytology of the pars distalis of pituitary green frog, Rana esculenta, was studied using various staining techniques. In general, besides the irregular occurrence of chromophobes, five chromophilic cell types were readily distinguishable (acidophils types 1 and 2, and basophils types 1, 2, and 3). The distribution of various cell types in the pars distalis has been described. The cytological modifications in the pars distalis of the male and female green frogs, gonadectomized during different periods of the sexual cycle, were studied at short and long intervals after gonadectomy. Administration of different doses of testosterone propionate and estradiol benzoate in the long-term castrates has been found effective in restoring the postgonadectomy changes. Similar treatment in the recently gonadectomized frogs prevented the occurrence of postgonadectomy changes. In general the basophils type 2 (B 2) exhibited the most profound modifications following gonadectomy and steroid hormone administration in both the male and female green frogs. The functional significance of the B 2 cells is discussed. It is suggested that these cells are the source of gonadotropic hormone(s) in this species.