[The in vivo measurement of ischemic myocardial interstitial metabolites in the beating canine heart: measurement of adenosine using an improved microdialysis technique].
The purpose of this study was 1) to evaluate the usefulness of myocardial microdialysis method in the beating canine heart for the measurements of myocardial interstitial adenosine, inosine and hypoxanthine concentrations and 2) to determine their changes during myocardial ischemia. Microdialysis probes modified for the beating myocardium were implanted in the left ventricular myocardium of pentobarbital-anesthetized dogs. The implanted microdialysis probes were perfused with saline solution containing low molecular heparin in order to prevent thrombotic obstruction of the dialysis membrane. The concentrations of adenosine and its metabolites, inosine and hypoxanthine, in the effluent dialysate were determined using high-performance liquid chromatography (HPLC). Dialysate concentrations of adenosine and its metabolites were considerably high immediately after the insertion of microdialysis probes. However, the concentrations gradually declined and stabilized by 150 min. Occlusion of the left anterior descending artery for 30 min caused a marked increase in dialysate adenosine and inosine levels, and a small increase in hypoxanthine level in the ischemic myocardium. These results suggest that the myocardial microdialysis method is very useful for the in vivo monitoring of interstitial levels of adenosine and its metabolites in the beating canine heart.
Makita
M
M
Department of Cardiovascular Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
D000241:Adenosine / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003327:Coronary Disease / Q000378:metabolism*; D003956:Dialysis / Q000379:methods*; D004285:Dogs; D005260:Female; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000032:analysis / Q000378:metabolism; D007288:Inosine / Q000032:analysis / Q000378:metabolism; D008297:Male; D008832:Microchemistry / Q000379:methods; D009206:Myocardium / Q000378:metabolism*
D007042:Hypoxanthines; D019271:Hypoxanthine; D007288:Inosine; D000241:Adenosine