ATRIAL-NATRIURETIC-PEPTIDE ALTERS NEITHER CAPILLARY FILTRATION NOR VASCULAR COMPLIANCE OF BOTH SKIN AND SKELETAL-MUSCLE OF HUMANS

We studied the effects of hANP99-126 on capillary filtration and venou s compliance in both the calf (mainly skeletal muscle) and foot (mainl y skin) of humans. Six healthy mean received ANP (intravenous injectio n of 25 mu g followed by continuous infusion of 0.1 mu g . kg(-1) . mi n(-1)) for 30 min. Another six men served as time controls. Capillary filtration coefficient, venous compliance, and also volume and blood f low of both calf and foot were measured repeatedly by occlusion plethy smography before, during, and after ANP. Additionally, we determined h ematocrit, central venous pressure, venous pressure in the foot, arter ial pressure, and heart rate. Filtration coefficients, venous complian ce, blood flow of both calf and foot as well as arterial blood pressur e did not change systematically during the infusion of ANP, and yet le g volume and central venous pressure (3.1 +/- 0.8 cm H2O) decreased wh ile both hematocrit (3.1 +/- 1.0%) and heart rate (17 +/- 11 min(-1)) increased. Thus, the ANP-evoked decrease in central venous pressure an d increase in hematocrit are unrelated to blood pooling or increases i n capillary filtration in skeletal muscle and skin of healthy humans.