Restoration of the Renin-Angiotensin System Balance Is a Part of the Effect of Fasting on Cardiovascular Rejuvenation: Role of Age and Fasting Models

Rejuvenation Res. 2020 Aug;23(4):302-312. doi: 10.1089/rej.2019.2254. Epub 2019 Nov 8.

Abstract

Intermittent fasting (IF) is an intervention that can be beneficial for health span and mitigate the risk of developing age-related cardiovascular diseases; however, the involved mechanisms are not well understood. The present study investigated the effects of IF regimens on the plasma level of angiotensin II (Ang II), and the expression of Ang II receptors (AT1aR and AT2R) and angiotensin-converting enzyme 2 (ACE2) in the heart and aorta of male, 3-, 12-, and 24-month-old Wistar rats fed ad libitum (AL), fed ad libitum and fasted 1 day per week (FW), or fasted every other day (EOD) for 3 months. Aging was associated with high circulating levels of Ang II, high level of AT1aR protein expression in the heart and aorta, and low level of AT2R protein expression in the heart and aorta. Both FW and EOD decreased Ang II levels (p < 0.01, p < 0.001) and AT1aR protein expression in the heart (p < 0.01, p < 0.001) and aorta (p < 0.001) of old rats. Both FW and EOD increased the expression of AT2R protein in the heart (p < 0.05 and p < 0.001, respectively). However, only EOD increased the expression of AT2R protein (p < 0.05) in the aorta. In the old group, both the FW and EOD regimens induced a significant increase in the expression of ACE2 protein in the heart (p < 0.01, p < 0.001 vs. age-matched AL group, respectively). The results suggest that a part of the recovery effect of fasting on cardiovascular system in old rats is mediated through restoration of the balance of renin-angiotensin system.

Keywords: aging; cardiac hypertrophy index; intermittent fasting; renin–angiotensin system (RAS).

MeSH terms

  • Aging*
  • Animals
  • Fasting*
  • Heart / physiology*
  • Male
  • Rats
  • Rats, Wistar
  • Recovery of Function*
  • Rejuvenation / physiology*
  • Renin-Angiotensin System / physiology*