Clofibrate improves myocardial ischemia-induced damage through regulation of renin-angiotensin system and favours a pro-vasodilator profile in left ventricle

J Pharmacol Sci. 2020 Dec;144(4):218-228. doi: 10.1016/j.jphs.2020.09.005. Epub 2020 Sep 18.

Abstract

Myocardial ischemia initiates a chain of pathological conditions leading to cardiomyocyte death. Therefore, pharmacological treatment to stop ischemia-induced damage is necessary. Fibrates, have been reported to decrease inflammatory markers and to modulate the renin-angiotensin system (RAS). Our aim was to explore if clofibrate treatment, administered one week after myocardial event, decreases MI-induced cardiac damage. Wistar rats were assigned to: 1. Sham or 2. Coronary artery ligation (MI). Seven days after, rats were subdivided to receive vehicle (V) or clofibrate [100 mg/kg (C)] daily for 7 days. Blood samples and left ventricle were analyzed. RAS components [angiotensin II, angiotensin converting enzyme (ACE), and AT1-receptor] decreased in MI-C compared to MI-V, while [Ang-(1-7), bradykinin, ACE-2, and AT2-receptor] raised in response to clofibrate treatment. Oxidative stress markers increased in MI-V rats, a profile reverted in MI-C rats. Nitric oxide (NO) pathway (Akt, eNOS, and NO) exhibits a lower participation in MI-V, but clofibrate raised NO-pathway components and its production. MI-induced fibrosis and structural damage was also improved by clofibrate-treatment. In conclusion, clofibrate administration to 7 days MI-rats exerts an antioxidant, pro-vasodilator expression profile, and anti-fibrotic effect suggesting that PPARα activation can be considered a therapeutic target to improve cardiac condition posterior to ischemia.

Keywords: Fibrates; Myocardial infarction; Nitric oxide; Oxidative stress; Renin-angiotensin system.

MeSH terms

  • Angiotensin II / metabolism
  • Animals
  • Clofibrate / administration & dosage*
  • Clofibrate / pharmacology*
  • Fibrosis
  • Heart Ventricles / metabolism*
  • Heart Ventricles / pathology
  • Male
  • Myocardial Ischemia / drug therapy*
  • Myocardial Ischemia / metabolism*
  • Myocardial Ischemia / pathology
  • Myocardium / pathology*
  • Nitric Oxide / metabolism*
  • Oxidative Stress / drug effects
  • Peptidyl-Dipeptidase A / metabolism
  • Rats, Wistar
  • Receptor, Angiotensin, Type 1 / metabolism
  • Renin-Angiotensin System / drug effects*
  • Time Factors

Substances

  • Receptor, Angiotensin, Type 1
  • Angiotensin II
  • Nitric Oxide
  • Peptidyl-Dipeptidase A
  • Clofibrate