期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1998
卷号：95
期号：18
页码：10990-10995
DOI：10.1073/pnas.95.18.10990
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Catecholamines, thought to derive from the extrinsic innervation of the ovary, participate in the regulation of ovarian development and mature gonadal function. Recently, intraovarian neurons containing tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, were described in the ovary of nonhuman primates. We now show that the primate ovary expresses both the genes encoding TH and dopamine {beta}-hydroxylase (DBH), the key enzymes in norepinephrine (NE) biosynthesis. Ovarian neurons were identified as a site of TH and DBH gene expression, and surprisingly, oocytes were identified as an exclusive site of DBH synthesis. Oocytes contain neither TH mRNA nor protein, indicating that they are unable to synthesize dopamine (DA). They did, however, express a DA transporter gene identical to that found in human brain. The physiological relevance of this transporter system and DBH in oocytes was indicated by the ability of isolated oocytes to metabolize exogenous DA into NE. Isolated follicles containing oocytes--but not those from which the oocytes had been removed--responded to DA with an elevation in cAMP levels; this elevation was prevented by propranolol, a {beta}-adrenoreceptor antagonist. The results suggest that oocytes and somatic cells are linked by a neuroendocrine loop consisting of NE synthesized in oocytes from actively transported DA and cAMP produced by somatic follicular cells in response to NE-induced {beta}-adrenoreceptor activation.
