MICRODIALYSIS STUDY OF RELEASE OF ADENINE-NUCLEOTIDE BREAKDOWN PRODUCTS INTO THE MYOCARDIAL INTERCELLULAR SPACE DURING ISCHEMIA AND REPERFUSION

Adenosine (A) is one of the most important regulators of coronary vascular tone [4, 8]. At the present time changes in the A concentration in the intercellular space of the myocardium are judged on the basis of its concentration in the coronary venous outflow or in the transudate collected from the epicardial surface of the heart [5, 6]. In this communication we suggest a more direct method of determining extracellular A, based on perfusion of the rat heart by means of a microdialysis apparatus, implanted into the wall of the left ventricle, followed by determination of levels of adenosine nucleotide breakdown products (ANBP), namely A, inosine (I), and hypoxanthine (HX) in the dialysate. The microdialysis technique has already found wide application in neurophysiological and neuropharmacological research for quantitative analysis of neurotransmitters and other products in the extracellular space in various parts of the brain [9, 10]. It enables local changes in the concentration of ANBP, including A, to be assessed during ischemia and reperfusion of the heart.