Effects of angiotensin II on fluid transport, transmural potential difference and blood flow by rat jejunum in vivo.

A method has been described for the measurement of fluid transport by rat jejunum in vivo over two consecutive 30 min periods. 2. Subpressor infusion rates of angiotensin (0-59 ng/kg per minute) stimulate fluid transport, while high (pressor) infusion rates (590 ng/kg per minute) inhibit fluid absorption. 3. Both the inhibitory and stimulatory effects of angiotensin on fluid transport are not accompanied by any change in the transmural p.d., total blood flow to the jejunum or distribution of blood flow within the wall of the jejunum. 4. These results are discussed in relation to the mechanism of action of angiotensin on fluid transport and its role in sodium and water homoeostasis.