Stimulation of proximal tubular sodium reabsorption by ile5 angiotensin II in the rat kidney.

A direct dose-dependent stimulation or inhibition by val5-angiotensin II of sodium reabsorption in the rat proximal nephron has been shown using stationary microperfusion combined with perfusion of the peritubular capilaries. Since the circulating form of the hormone in the rat has been suggested to be the ile5-analogue these experiments have been repeated using the ile5-peptide at peritubular concentrations covering the normal physiological range (10-10 -10-13M). Comparison of the results with the previously published data shows no significant difference between the actions of these two analogues. At the concentrations tested both caused significant stimulation of sodium reabsorption with a maximum effect at 10(-11)M.