Reperfusion with adenosine and nitroprusside improves preservation of isolated guinea pig hearts after 22 hours of cold perfusion with 2,3 butanedione monoxime.

The function of isolated guinea pig hearts treated with 2,3 butanedione monoxime (BDM) before, during, and initially after 22 h of hypothermic perfusion was examined during 4 h of normothermic reperfusion. BDM is a vasodilatory and negative inotropic agent that reversibly decreases sensitivity of contractile proteins to Ca2+. Also examined were the effects of adenosine (ADE) and nitroprusside (NP) in improving coronary flow (CF) and contractile function when given with BDM during rewarming and during the initial period of normothermic reperfusion. Isovolumetric left ventricular pressure (LVP), CF, and percentage of O2 extraction (%O2E) were measured in Krebs-Ringer-perfused hearts divided into three groups of 11 hearts each: drug-free controls (0 BDM); 10 mM BDM alone; and 10 mM BDM + 10 microM ADE + 100 microM NP. BDM was given 20 min before hypothermia, during hypothermia (3.8 degrees +/- 0.1 degree C) for 22 h, and for 30 min after rewarming to 37 degrees +/- 0.1 degree C; ADE was given with NP for only 20 min before and during rewarming and for 30 min after rewarming. Hearts were perfused at low constant flow with oxygenated Krebs' solution during hypothermia. After 2.5-h normothermic reperfusion, LVP (initial controls 108 +/- 6 mm Hg) increased more with BDM + ADE + NP (80 +/- 4% of control) than with BDM alone (62 +/- 3%) or without BDM (28 +/- 5%). CF (controls 6.0 +/- 0.5 ml/g/min) decreased less with BDM + ADE + NP (77 +/- 4% of control) than with BDM alone (60 +/- 5%) or without BDM (53 +/- 6%).(ABSTRACT TRUNCATED AT 250 WORDS)