[Aspartic Acid and mannitol enhance protective efficiency of asanquineous cardioplegic solution].
The aim of this work was to assess effects of a novel asanquineous cardioplegic solution (CP-5), buffered with trisamine (pH 7.6+/-0.1 at 22 degrees C) and containing 21.5 mM aspartic acid and 20.0 mM mannitol, on postischemic functional and metabolic recovery of isolated rat heart. A modified Ringer solution with 25 mM KCl (pH 7.6+/-0.1 at 22 degrees C) and the St. Thomas' cardioplegic solution (pH 7.8+/-0.1 at 22 degrees C) were used as controls. Osmolarity of all cardioplegic solutions were 340+/-5. After 20-min initial perfusion according to Neely (steady state) the hearts were subjected to 40-min normothermal total ischemia followed by 30-min antegrade reperfusion. Cardioplegic solutions were infused prior to ischemia at rate of the initial coronary flow for 5 min at room temperature. During reperfusion the hearts of CP-5 group completely recovered coronary flow and significantly enhanced restoration of the majority functional indices compared to the hearts in both control groups. This effect was combined with less lactate accumulation and preservation of higher ATP and phosphocreatine (PCr) levels in the heart tissue by the end of ischemia and, probably was induced by inclusion of aspartic acid into composition of CP-5. By the end of reperfusion the hearts treated with CP-5 completely recovered PCr content and restored ATP level up to 65.2+/-4.6% of initial one. A better energy state of reperfused hearts in CP-5 group was accompanied by reduction of myocardial lactate tissue to the preischemic value. Restoration of ATP, PCr and lactate content was significantly poor in both control groups during reperfusion. The least formation of a spin adduct of the short life oxygen radicals was found in the myocardial effluent of the hearts of CP-5 group at the early reperfusion using EPR technique. These data suggest a reduced release of oxygen radical generating systems from postischemic myocardium into perfusate due to antioxidant effect of mannitol. The obtained results substantiate addition of aspartic acid and mannitol to the asanquineous cardioplegic solution, buffered with trisamine, to enhance efficacy of myocardial protection against ischemia and reperfusion injury.
Pisarenko
O I
OI
Cardiology Research Complex; ul. Tretiya Cherepkovskaya, 15a, 121552 Moscow, Russia.
Shul'zhenko
V S
VS
Studneva
I M
IM
Timoshin
A A
AA
D000818:Animals; D001224:Aspartic Acid; D002314:Cardioplegic Solutions; D006321:Heart; D008274:Magnesium / Q000494:pharmacology; D008353:Mannitol; D017208:Rats, Wistar
D002314:Cardioplegic Solutions; D001224:Aspartic Acid; D008353:Mannitol; D008274:Magnesium