Effect of chemical sympathectomy and ganglion blockade on angiotensin-stimulated fluid absorption in the rat jejunum.

A study has been made of the effects of chemical sympathectomy and ganglion blockade on the responses of rat jejunum in vivo to intravenous doses of angiotension and noradrenaline capable of stimulating fluid transport. Pretreatment with 6-hydroxydopamine (chemical sympathectomy) or pentolinium tartrate (ganglion blockade) abolished the stimulatory actions of angiotensin II but left the responses to noradrenaline unimpaired. Dopamine, like noradrenaline, stimulated fluid transport but this response required very high dopamine infusion rates, was refractory to the dopamine antagonist sulpiride and was inhibited by the alpha- blocker phentolamine. The possible interaction between angiotensin and the intestinal sympathetics is discussed with reference to control in extracellular fluid volume.