Reduced dipsogenic responsiveness to intracerebroventricularly administered angiotensin II in estrogen-treated rats.
Chronic administration of two doses of estradiol benzoate (30 and 46 micrograms/kg/day) reduced the drinking response to acute administration of either isoproterenol (25 micrograms/kg, s.c.), the beta-adrenergic agonist, or angiotensin II (Ang II) (200 micrograms/kg, s.c.). The drinking response to intracerebroventricular administration of Ang II (40 ng/kg), but not carbachol (800 ng/kg), was also attenuated in estrogen-treated rats. An assessment of the Ang II binding in a diencephalic block of tissue from estrogen-treated rats revealed a significant reduction compared to untreated controls. The results suggest, but do not prove, that the reduced drinking response observed in estrogen-treated rats may be related to a reduction in the number of Ang II receptors in the brain.
D000804:Angiotensin II / Q000008:administration & dosage*; D000818:Animals; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology; D004327:Drinking Behavior / Q000187:drug effects*; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007276:Injections, Intraventricular; D007545:Isoproterenol / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013894:Thirst / Q000187:drug effects*; D013997:Time Factors; D014599:Uterus / Q000033:anatomy & histology
D000804:Angiotensin II; D004958:Estradiol; D002217:Carbachol; D007545:Isoproterenol