[Digestive process and regulation of renal excretory function: pepsanurin and prokinin inhibit the natriuretic peptide diuretic action].

In order to clarify the blunting effect of peptides released by pepsin from blood plasma on ANP diuretic action, two prokinins designated PU-18 and PU-16 were tested. Both of them were able to inhibit in nanomolar doses the diuretic-saluretic action of 0.5 ug i.v. bolus of ANP given to anesthetized rats either by intravenous route or introduced in the duodenal lumen. PU-16 in doses of 0.5 and 1 ug were able to reduce in 72 and 96.5% respectively the natriuresis induced by 0.5 ug intravenous bolus of ANP. The data support the hypothesis that prokinins liberated in the digestive tract, could be physiological factors involved in hydrosaline homeostasis, moderating the ANP mediated increase of water, Na and K excretion during digestion.