Role of brain angiotensin II in renal nerve inhibition elicited by volume expansion in the conscious rabbit.

Losartan (10 microg/25 microl) or vehicle was injected into the fourth brain ventricle prior to volume expansion (VE) with Haemaccel (2 ml/min for 30 min). RSNA was reduced by a maximum of 45% in response to the VE following vehicle and by 33% following losartan. There was no significant difference between the treatments in RSNA, nor in the blood pressure and heart rate responses. We conclude that endogenous angiotensin II does not make a major contribution to the reflex reduction in RSNA initiated by VE.