Differential effects of late-life initiation of low-dose enalapril and losartan on diastolic function in senescent Fischer 344×Brown Norway male rats

Academic Article

Abstract

  • No proven pharmacological therapies to delay or reverse age-related diastolic dysfunction exist. We hypothesized that late-life low-dose (non-bloodpressure- lowering) angiotensin-converting enzyme inhibition vs. angiotensin II receptor blockade would be equally efficacious at mitigating diastolic dysfunction in the senescent Fischer 344×Brown Norway rat. Enalapril (10 mg/kg/day; n=9) initiated at 24 months of age and continued for 6 months, increased myocardial relaxation (e'), reduced Doppler-derived indices of filling pressure (E/e'), favorably lowered the ratio of phospholamban-SERCA2 and reduced oxidative stress markers, Rac1 and nitrotyrosine, in aged hearts. Treatment with losartan (15 mg/kg/day; n=9) similarly mitigated signs of cardiac oxidative stress, but impairments in diastolic function persisted when compared with untreated rats (n=7). Our findings favor the idea that the lusitropic benefit of low-dose angiotensinconverting enzyme inhibitor initiated late in life may be related to an antioxidant-mediated modulation of SERCA2, resulting in improved relaxation rather than via overt effects on cardiac structure or blood pressure. © The Author(s) 2011.
  • Authors

    Published In

  • AGE  Journal
  • Digital Object Identifier (doi)

    Author List

  • Groban L; Lindsey S; Wang H; Lin MS; Kassik KA; Machado FSM; Carter CS
  • Start Page

  • 831
  • End Page

  • 843
  • Volume

  • 34
  • Issue

  • 4