Local intravascular infusion with porcine hypothalamic extract changed the cytology and stimulated the secretory activity of rat pituitary autografts.

Abstract

The long-term effect of infusing porcine hypothalamic median eminence extract (MEE) into the local vascular supply of rat pituitary autografts was tested. Fifty rats were hypophysectomized and the pars distalis transplanted to the hilus of the kidney. Continuous infusion of the graft (via the renal artery) in 40 of these animals started 14 days after the initial operation and continued for 14 or 28 days. Infusion with MEE (10 animals) resulted in a very striking increase in the size of gonadotrophs and some enlargement in thyrotrophs. This treatment also induced secretion of gonadotrophins and thyrotrophin (TSH) as evidenced by ovarian follicular development and increased thyroid epithelial cell height. The secretion of adrenocorticotrophin (ACTH) may have also been stimulated. These results were not observed when the grafts were infused with cerebral cortical extract, vasopressin, oxytocin or when hypophysectomized animals received MEE by continuous intravenous infusion. These results suggest that porcin...