Endogenous inhibitor of Na-K-Cl cotransport system in inbred Dahl rats

The urinary excretion and plasma concentrations of cotransport inhibitory factors (CIF) were analyzed in prehypertensive Dahl salt-sensitive rats (DS) to determine the role of the DS Na-K-Cl cotransport system. Analysis of CIF excretion and plasma concentrations in DS and Dahl salt-resistant rats (DR) indicated the presence of elevated sodium and water excretion in DS compared to DR. Furthermore, DS exhibited increased plasmatic and urinary CIF levels which acted as a compensatory mechanism against enhanced chloride reabsorption at the thick ascending limb of Henle's loop.