Water drinking and the effect of angiotensin and renin in a dasyurid marsupial (Antechinus stuartii).
Marsupial mice, Antechinus stuartii, were given intraperitoneal (ip) injections of 1-30 micrograms of Val5-angiotensin II amide to determine whether it had any effect on thirst. Drinking in the first hour after injection and measured water intake over 2 and 24 hr were not substantially increased compared with controls. Intraperitoneal injection of sheep renin had no effect on water intake. Water deprivation increased 2- and 24-hr water intake. Sheep renin and Val5-angiotensin II amide elicited pressor responses after ip injection. By comparison, rats given 100 micrograms of Val5-angiotensin II amide ip increased water intake in the first 2 hr after injection compared with saline-injected and noninjected controls. The results suggest that the thirst mechanism in Antechinus is insensitive to exogenous and to low levels of endogenous circulating angiotensin II. The explanation of this difference from other mammals may be found in evidence that the thirst mechanism in species which do not normally drink water in nature is relatively insensitive to exogenous angiotensin.
D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004326:Drinking / Q000187:drug effects*; D005260:Female; D007274:Injections, Intraperitoneal / Q000662:veterinary; D008394:Marsupialia / Q000502:physiology*; D051381:Rats / Q000502:physiology; D011919:Rats, Inbred Strains; D012083:Renin / Q000494:pharmacology*; D013045:Species Specificity; D014868:Water Deprivation / Q000502:physiology
D000804:Angiotensin II; D012083:Renin