The Presence of Gonadotropic and Thyrotropic Cells in the Pituitary Pars Tuberalis of the Monkey (Macaca mulatta)1

Abstract

The objective was to determine by means of immunocytochemistry if cells containing hormones of the pituitary pars distalis can be demonstrated in the pars tuberalis of the monkey (Macaca mulatta). For this purpose seven animals representing both sexes were used. Localization of hormones was accomplished with the peroxidase-antiperoxidase method of Sternberger, utilized with antisera to the following human hormonal preparations: somatotropin, mammotropin,β ^l-24-corticotropin, chorionic gonadotropin, and the β-subunits of follicle-stimulating hormone and thyrotropin. A large proportion of the parenchymal cells in the pars tuberalis associated with the median eminence was composed of gonadotropic cells, probably containing both luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and of thyrotropic cells. Corticotropic and somatotropic cells were rare and mammotropic cells could not be detected. Thus, the monkey pars tuberalis appears competent to secrete LH, FSH and thyrotropin.