title: Nitric oxide synthase in the rat anterior pituitary gland and the role of nitric oxide in regulation of luteinizing hormone secretion.
abstract: By using immunohistochemistry and in situ hybridization, we have demonstrated that the nitric oxide (NO)-synthesizing enzyme NO synthase is present in gonadotrophs and in folliculo-stellate cells of the anterior pituitary gland of male and female rats. A marked increase in levels of NO synthase protein and mRNA was observed after gonadectomy. In vitro studies on dispersed anterior pituitary cells suggest that NO inhibits gonadotropin-releasing-hormone-stimulated luteinizing hormone release. An inhibitory effect of NO has also been shown on growth-hormone-releasing-hormone-stimulated release of growth hormone [Kato, M. (1992) Endocrinology 131, 2133-2138]. Thus these findings support a dual mechanism for NO in the control of anterior pituitary hormone secretion, an autocrine mediation of luteinizing hormone release on gonadotrophs, and a paracrine effect on growth hormone secretion involving folliculo-stellate cells closely related to somatotrophs. We speculate that NO may participate in producing the pulsatile secretion patterns of these two pituitary hormones.
authors.affiliation: Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Ceccatelli
authors.forename: A L
authors.initials: AL
authors.lastname: Hulting
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Gustafsson
authors.forename: M
authors.initials: M
authors.lastname: Villar
authors.forename: T
authors.initials: T
authors.lastname: Hökfelt
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D015870:Gene Expression; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D017403:In Situ Hybridization; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D009919:Orchiectomy; D010052:Ovariectomy; D010903:Pituitary Gland, Anterior / Q000201:enzymology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000494:pharmacology
chemical_list: D004967:Estrogens; D012333:RNA, Messenger; D009569:Nitric Oxide; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases