[Method of quantitative determination of natriuretic factor in biological fluids]

The natriuretic factor was determined quantitatively on the isolated rat jejunum segmens turned inside out. After addition of the test blood plasma into the incubation medium the changes in fluid absorption by the intestinal epithelium were recorded. The amount of the natriuretic factor capable of complete blocking the transport activity of the intestinal epithelium was accepted as 1 intestinal unit of the natriuretic factor.