[The clinical significance of natriuretic hormones]

Out of all until now discovered natriuretic factors it is still the atrial natriuretic factor (ANF) which is the most significant with its diuretic, natriuretic and vasodilatory effects. Its effect is antagonistic to sodium retention factors. The increase of its levels in arterial hypertension is more of secondary character, but according to some authors the functional deficit of ANF secretion can be applied also primarily in the development and maintenance of high blood pressure. ANF levels represent a good marker of the clinical severeness and are of prognostic value. Increased levels were detected also in cases of renal failure and partially in hepatic cirrhosis. Natriuretic hormone, in comparison to ANF, is a natriuretic and vasoconstrictive substance, the effect of which is based on the mechanism of sodium pump inhibition. Chemically the main candidate is represented by endogenous ouabain, or a digitalis-like activity. It increases physiologically due to the expansion of extracellular fluid during gravidity and in newborn. Its pathological increase is brought about by some forms of essential hypertension and in the diseases associated with fluid retention and edema development. Cirrhosis of the liver can reflect both the degree of sodium retention and haemodilution, as well as the severeness of hepatic lesion. (Tab. 2, Ref. 30.).