The influence of the atrial natriuretic factor on venous tone in man

To assess the effect of the human atrial natriuretic factor (ANF) in vivo on human veins, a series of investigations was done on the dorsal hand vein of 11 healthy volunteers (ten men, one woman), aged from 25 to 49 years. In the case of intact veins the human ANF effect was evaluated by the "venoconstriction" test; on veins constricted by a reflex sympathetic discharge, the ANF effect was evaluated by the test of "venous reflexes", and on veins constricted with serotonin and angiotensin II by the "preconstriction" test. The results were expressed in venoconstrictive units (VCU). ANF was injected into the vein under study in increasing bolus doses (from 50 pg to 500 ng). The results indicate that this peptide did not affect either intact veins or these constricted by sympathetic discharge. On veins preconstricted with serotonin, ANF had a slight, statistically insignificant effect (848.57 +/- 378.67 VCU 30 sec before, compared to 670.00 +/- 460.25 VCU 30 sec after the injection of 50 pg; n = 7; p greater than 0.05), up to a maximal local dose of 500 ng. The same was true for the vein preconstricted with angiotensin II. It is concluded that the human atrial natriuretic factor has no significant influence on peripheral venous tone in man.