Effect of endurance exercise on cardiac secretion and renal clearance of atrial natriuretic peptide in normal humans.
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: 42.6 +/- 13.2 ng/ml, trained: 47.4 +/- 17.9 ng/ml, p n.s.). Renal extraction of ANP was 72 +/- 4% before training, and unchanged (66 +/- 5%) after the exercise period. Renal clearance of ANP was also unaltered by training (514.2 +/- 48.4 ml/min before, and 508.9 +/- 74.8 ml/min after training, p n.s.). We conclude that as ANP release is not increased by training, the peptide does not account for the anti-hypertensive effect of endurance exercise. Other humoral and/or neural mechanisms possibly mediate the beneficial haemodynamic effects of training.
Sudhir
K
K
Alfred and Baker Medical Unit, Alfred Hospital, Prahran, Victoria, Australia.
Meredith
I T
IT
Jennings
G L
GL
Friberg
P
P
Woods
R L
RL
Esler
M D
MD
D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001794:Blood Pressure / Q000502:physiology; D006321:Heart / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009318:Natriuresis; D010807:Physical Endurance; D012016:Reference Values; D012146:Rest
D009320:Atrial Natriuretic Factor