Fetal or Material Hypophysectomy in Rhesus Monkeys (Macaca mulatta): Effects on the Development of Testes and Other Endocrine Organs

Open Access
Publisher Website
Google Scholar
Abstract
To assess whether or not development of fetal testes and other endocrine organs is dependent on maternal or fetal pituitary secretions, we ablated the fetal or maternal pituitary during pregnancy of the rhesus monkey (Macaca mulatta). Fetal hypophysectomy was performed between 111 and 116 days of gestation. Maternal hypophysectomy was performed between 56 and 73 days of pregnancy. Completeness of hypophysectomy was confirmed by histological examination of the sella turcica of the operated animals. Quantitative study was performed on serially sectioned testes. Removal of either the fetal or maternal hypophysis led to a reduced body weight, although it was more severe after ablation of the fetal hypophysis. Compared to intact controls, infant adrenal weights were elevated following maternal hypophysectomy, but were reduced (P<0.05) markedly after fetal hypophysectomy. Ablation of the fetal hypophysis reduced (P<0.05) infant thyroid weight, whereas removal of the maternal pituitary had no discernable effect. After fetal hypophysectomy, infant testis weights were reduced threefold (P<0.05) as compared to intact control infants. The percentage of Leydig cells, as well as spermatogonia per testis, was significantly decreased (P<0.05) in infants lacking their pituitary. Seminiferous cord diameter remained fairly constant in testes of all groups of fetuses and infants examined. These results indicate the dependence of fetal testis, adrenals and thyroids on endogenous secretions of the fetal pituitary for normal intrauterine growth and development of rhesus monkeys.