title: Angiotensin-(1-7): a novel peptide in the ovary.
abstract: The present study was undertaken to investigate the presence of angiotensin-(1-7) [Ang-(1-7)] in the ovary and a possible role for it. Cycling female rats were killed in each phase of the estrous cycle, and ovarian Ang II and Ang-(1-7) were separated by HPLC and measured by RIA. The mean levels of Ang-(1-7) in proestrus and estrus were significantly higher than those in metestrus and diestrus (P < 0.05). Ang-(1-7) was also significantly higher in equine chorionic gonadotropin (eCG)-treated immature rats. Ang-(1-7) induced a significant increase in estradiol and progesterone production (P < 0.05) in the ovary of immature rats (24-25 d old) pretreated with eCG and perfused in a closed circuit system. This effect was blocked by A-779, a specific Ang-(1-7) antagonist (P < 0.05). The present data demonstrate the presence and physiological role of a novel renin-Ang system peptide in the ovary. The higher level of Ang-(1-7) in proestrus and estrus as well as in eCG-treated rats suggests the involvement of this renin-Ang system peptide in pre- and postovulatory events.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, 31270-901 Belo Horizonte, Brazil.
authors.forename: Amilton P R
authors.initials: AP
authors.lastname: Costa
authors.forename: Christiane R
authors.initials: CR
authors.lastname: Fagundes-Moura
authors.forename: Virginia M
authors.initials: VM
authors.lastname: Pereira
authors.forename: Leonardo F
authors.initials: LF
authors.lastname: Silva
authors.forename: M Aparecida R
authors.initials: MA
authors.lastname: Vieira
authors.forename: Robson A S
authors.initials: RA
authors.lastname: Santos
authors.forename: Adelina M
authors.initials: AM
authors.lastname: Dos Reis
mesh_terms: D000803:Angiotensin I / Q000378:metabolism / Q000502:physiology*; D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004971:Estrus / Q000378:metabolism; D005260:Female; D006736:Horses; D066298:In Vitro Techniques; D009994:Osmolar Concentration; D010053:Ovary / Q000378:metabolism*; D010446:Peptide Fragments / Q000502:physiology*; D011359:Proestrus / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006063:Chorionic Gonadotropin; D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)