Centrally injected atrial natriuretic factor inhibits angiotensin- and osmotically-induced drinking in pigs

Atrial natriuretic factor 5-28 (atriopeptin III, APIII; 10 micrograms) injected into the cerebral ventricles of young pigs 5 min before injection of either angiotensin II (AII, 300 ng) or hypertonic NaCl (0.74 M) attenuated the subsequent drinking responses to these dipsogens although the latency to the response was not altered. The inhibition lasted for up to 4 days in the case of AII-induced drinking but normal daily water intake was not disrupted. These findings suggest that in the pig APIII may play a role in the central regulation of drinking in response to AII and that it may have a long biological half-life.