Acute exercise alters circulating and local tissue renin‐angiotensin systems

Abstract

Although the renin‐angiotensin system (RAS) plays an intricate role in coordinating vascular adaptations to exercise, there is a paucity of information regarding changes to circulating and local RAS associated with acute exercise. Thus, we investigated the modifications to circulating, aorta and kidney RAS in exercised male Sprague Dawley rats. Rats were exercised for 1h and euthanized immediately (IPEx) or 24h post exercise (24PEx, n=10 per group). Compared to non exercised control (CON), plasma ACE activity decreased IPEx, while 24PEx activity decreased further (85.61 ± 3.53 U/L; 75.28 ± 2.87 U/L; 62.03 ± 3.33 U/L, p<0.05 (U = μmol/min)). Plasma angiotensin II levels were increased IPEx (77.04 ± 16.71 pg/mL vs. 151.22 ± 25.42 pg/mL, p<0.05), but 24PEx levels were comparable to CON (81.19 ± 13.62 pg/mL, p>0.05). Compared to CON, aorta ACE activity decreased IPEx and remained blunted 24PEx (0.798 ± 0.03 U/g; 0.661 ± 0.05 U/g; 0.572 ± 0.03 U/g, p<0.05). Aorta ACE protein decreased ∼42% IPEx compared to CON and 24PEx (p<0.05). Kidney ACE activity increased IPEx (CON: 0.526 ± 0.03 U/g; IPEx: 0.648 ± 0.04 U/g; 24PEx: 0.489 ± 0.03 U/g, p<0.05). Upregulation of kidney ACE protein was observed IPEx (+42%) and 24PEx (+77%) (p<0.05). This study highlights changes in systemic and organ‐specific local RAS in response to acute exercise, which may be essential to the beneficial changes observed in chronic exercise.Funding: NSERC / HSFO