Effect of Endurance Exercise on Cardiac Secretion and Renal Clearance of Atrial Natriuretic Peptide in Normal Humans

Abstract

Previous work from our laboratory has shown that (i) regular endurance exercise lowers blood pressure (BP), and (ii) acute exercise increases circulating levels of atrial natriuretic peptide (ANP). We hypothesised that increased ANP release may contribute to the antihypertensive effect of regular exercise. Using arterial and selective venous (coronary sinus and renal vein) catheterization and sampling, we measured cardiac secretion and renal clearance of ANP at rest in 7 normal healthy males (mean age 36 years), before and after 4 weeks of training. Body weight and haematocrit remained unchanged. Systolic BP fell by 10 mmHg with training (p=0.008), diastolic BP fell by 6 mmHg (p=0.006) and heart rate decreased by 9 beats/minute (p=0.002), but central venous pressure remained unchanged. Arterial, coronary sinus and renal vein ANP concentrations did not change with training. There was no significant rise in cardiac secretion of ANP with training (sedentary: 42.613.2 ng/ml, trained: 47.417.9 ng/ml, p n.s.). Renal extraction of ANP was 724% before training, and unchanged (665%) after the exercise period. Renal clearance of ANP was also

Key Words:

• Endurance exercise
• Blood Pressure Changes
• Atrial Natriuretic Peptide