Abstract

There are reports which indicate that some steroid derivatives have activity atcardiovascular level; nevertheless, there is scarce information about the effects exerted by the progesterone derivatives on cardiac injury caused by ischemia/reperfusion. In this study, a new steroid (progesterone derivative) was synthetized with the objective of evaluating its activity on ischemia/reperfusion injury. The Langendorff technique was used to evaluate the effect of progesterone derivative on ischemia/reperfusion injury. Additionally, molecular mechanism involved in the activity exerted by the progesterone derivative on perfusion pressure and coronary resistance was evaluated by measuring left ventricular pressure in absence or presence of following compounds; mifepristone, prazosin, metoprolol, indomethacin and nifedipine. The results showed that the progesterone derivative reduces infarct size compared with control. Other results showed that the progesterone derivative significantly increase (p = 0.05) the perfusion pressure and coronary resistance in isolated heart. Other data indicate that the progesterone derivative increase left ventricular pressure in a dose-dependent manner (0.001 to 100 nM); however, this phenomenon was significantly inhibited by nifedipine at a dose of 1 nM (p = 0.05). In conclusion, these data suggest that progesterone derivative exert acardioprotective effect via the calcium channels activation and consequently induces changes in the left ventricular pressure levels. This phenomenon results in decrease of myocardial necrosis after ischemia and reperfusion.

Key words: Steroid, progesterone, left ventricular pressure, indomethacin.