Affiliation:
1. Servicio de Endocrinología, Hospital Ramón y Cajal, 28034 Madrid, Spain
Abstract
Vasoactive intestinal polypeptide (VIP) content is increased in the hyperplastic pituitaries of estrogen (E)-treated rats, thus suggesting that this neuropeptide could mediate the E effect on lactotrophs. E also decreases pituitary TGF-β1 content, an autocrine/paracrine inhibitor of lactotroph proliferation, and induces pituitary angiogenesis. To elucidate the role of VIP in this context, lactotroph hyperplasia was induced in female Fisher 344 rats by implanting sc pellets of diethylstilbestrol (DES). Twenty-five days later, the rats were treated with three different increasing doses of a VIP receptor antagonist or the vehicle for 5 d. DES treatment resulted in a marked increase of serum prolactin (PRL), pituitary PRL content, PRL mRNA expression, pituitary weight, and pituitary proliferating cell nuclear antigen. DES treatment also increased pituitary VIP content and VIP mRNA levels, but not in the hypothalamus and cerebral cortex. Simultaneously, DES treatment decreased the pituitary TGF-β1 content and increased the pituitary content of vascular endothelial growth factor. VIP receptor antagonist partially reverted the effect of DES on serum PRL and pituitary PRL, proliferating cell nuclear antigen, TGF-β1, and vascular endothelial growth factor contents, as well as on pituitary weight, in a dose-dependent relation. These data suggest that pituitary VIP mediates the effect of E on lactotroph hyperplasia, pituitary TGF-β1, and angiogenesis.
Reference55 articles.
1. Effect of diethylstilbestrol-induced tumorigenesis on the secretory activity of the rat anterior pituitary gland.;Meyer;Endocrinology,1956
2. Time course of induction of PRL-secreting pituitary tumors with diethylstilbestrol in male rats. Response of tuberoinfundibular dopaminergic neurons.;Morgan;Endocrinology,1985
3. Estrogen induced hyperplasia and neoplasia in the rat anterior pituitary gland. An immunohistochemical study.;Lloyd;Am J Pathol,1983
4. Transforming growth factor-β1 mRNA and protein expression in the pituitary gland and its action on PRL-secretion and lactotropic growth.;Sarkar;Mol Endocrinol,1992
5. Effect of antisense suppression of transforming growth factor-β3 gene on lactotropic cell proliferation.;Hentges;J Neuroendocrinol,2001
Cited by
20 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献