Myocardial protection by Ethyl-isopropyl amiloride, a specific NA[+] -H[+] exchange inhibitor, following hemorrhagic shock

ABSTRACT

Hemorrhagic shock and resuscitation is well known to result in myocardial dysfunction and injury. Stimulation of the Na[+] -H[+] exchanger plays an important role in the pathway of myocardial injury. The purpose of the present study was to examine the protective effects of blocking the cardiac Na[+] -H[+] exchange, using 100mM ethyl-isopropyl amiloride [EIPA], a specific Na[+] -H[+] exchanger blocker, on myocardial contractile function on ex vivo resuscitation of isolated rat heart following one hour of hemorrhagic shock. Sprague- Dawley rats were assigned to hemorrhage, hemorrhage + EIPA, sham hemorrhage and sham hemorrhage + EIPA groups. Rats were hemorrhaged for one hour. Hearts were harvested and ex vivo treated and resuscitated by perfused in the Langendorff System. Myocardial function was determined. The results showed that inhibition of the Na[+] -H[+] exchanger using EIPA improved the post-resuscitation myocardial contractile function. Blocking the Na[+] -H[+] exchanger using 100mM EIPA following 60 minutes of hemorrhagic shock improved myocardial function