[The mutual effect of ultrasound stimulation and exogenous ATP on myocardial protection during cardiac arrest].
We have reported that ultrasound stimulations have a protective effect toward ischemic insult upon myocardial cells during cardioplegic arrest. However, the exact mechanism of ultrasound stimulation was not known. To elucidate this mechanism, we investigated the effect of ultrasound stimulation (UI) and/or 0.1 mMATP added to the cardioplegic solution (A) on ventricular function and adenine nucleotide changes in isolated perfused rat hearts. The hearts were perfused by working heart mode for 10 min. to determine baseline values of hemodynamic variables and they received infusion of cardioplegic solutions, followed by 20 min cardiac arrest with myocardial temperature 37 degrees C. Subsequently to the ischemic arrest, aerobic reperfusion was continued for 30 min. In group I, neither UI was irrigated nor ATP was added to cardioplegic solution. In group II and IV, ATP was added and in group III and IV, UI (1010 KHz, 0.25 W/cm2) was irrigated during cardiac arrest. Myocardial ATP was measured by Luciferase method. Myocardial ATP content after 20 min of cardiac arrest showed 12.4, 25.3, 14.5 and 32.5 (nmol/mg protein) in group I, II, III, and IV respectively, whereas it was 32.6 at the pre-ischemic cardiac arrest. The recovery of aortic output after 30 min of reperfusion revealed 30.9%, 78.9%, 79.6%, 85.4%. These data suggested the ATP depletion during cardiac arrest was attenuated by the UI and exogeneous ATP, resulted in the high recovery level of ventricular function during reperfusion.
Mochizuki
Y
Y
Department of Cardiovascular Surgery, Jikei University School of Medicine, Tokyo, Japan.
D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002314:Cardioplegic Solutions; D006324:Heart Arrest, Induced; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014022:Tissue Survival / Q000187:drug effects* / Q000528:radiation effects; D014464:Ultrasonic Therapy
D002314:Cardioplegic Solutions; D000255:Adenosine Triphosphate