L-NAME improves doxycycline and ML-7 cardioprotection from oxidative stress

Front Biosci (Landmark Ed). 2018 Jan 1;23(2):298-309. doi: 10.2741/4592.

Abstract

Matrix metalloproteinase-2 (MMP-2) mediated degradation of myosin light chain 1 (MLC1) and troponin I (TnI) contributes to myocardial ischemia/reperfusion (I/R) injury. Modifications of MLC1 triggered by oxidative stress are mediated by myosin light chain kinase (MLCK), nitric oxide synthase (NOS), and MMP-2. Previous studies have shown that inhibiting both MLCK and MMP-2 protects against I/R injury. Here, we hypothesized that the addition of NOS inhibitor (L-NAME) at subprotective concentration to the mixture of subprotective concentrations of ML-7 and doxycycline (Doxy), will increase a synergistic cardioprotection of Doxy and ML-7 during I/R. Isolated rat hearts were subjected to global ischemia without or with administration of the mixture of inhibitors. Markers of I/R injury were measured in hearts and coronary effluents. Addition of L-NAME to the mixture of Doxy and ML-7 led to full recovery of heart contractility in comparison to combination of Doxy and ML-7. Improved heart contractility was associated with reduced degradation of TnI and MLC1. The combined administration of NOS, MMP-2 and MLCK inhibitors provides a novel strategy to protect heart from I/R injury.

MeSH terms

  • Animals
  • Azepines / pharmacology*
  • Cardiotonic Agents / pharmacology
  • Doxycycline / pharmacology*
  • Drug Synergism
  • Enzyme Inhibitors / pharmacology
  • Heart / drug effects
  • Heart / physiopathology
  • Male
  • Matrix Metalloproteinase 2 / metabolism
  • Myocardial Reperfusion Injury / physiopathology
  • Myocardium / metabolism
  • Myosin-Light-Chain Kinase / antagonists & inhibitors
  • Myosin-Light-Chain Kinase / metabolism
  • NG-Nitroarginine Methyl Ester / pharmacology*
  • Naphthalenes / pharmacology*
  • Oxidative Stress / drug effects*
  • Rats, Wistar

Substances

  • Azepines
  • Cardiotonic Agents
  • Enzyme Inhibitors
  • Naphthalenes
  • ML 7
  • Myosin-Light-Chain Kinase
  • Matrix Metalloproteinase 2
  • Doxycycline
  • NG-Nitroarginine Methyl Ester