Headrick J P, Matherne G P, Berr S S, Han D C, Berne R M
Department of Physiology, University of Virginia, Health Sciences Center, Charlottesville 22908.
Am J Physiol. 1991 Jan;260(1 Pt 2):H165-72. doi: 10.1152/ajpheart.1991.260.1.H165.
Adenosine release into epicardial fluid and coronary effluent of isolated isovolumic guinea pig hearts was examined at baseline and after stimulation with norepinephrine (30 nM) during 31P-nuclear magnetic resonance spectroscopy to monitor myocardial metabolism. At baseline flow (9.6 +/- 0.3 ml.min-1.g-1), epicardial and venous adenosine concentrations were 154 +/- 40 and 17 +/- 5 nM, respectively. The phosphorylation potential (log[ATP]/[ADP][Pi]) and the phosphocreatine-inorganic phosphate ratio ([PCr]/[Pi]) were 5.26 +/- 0.04 and 8.5 +/- 0.7, respectively. Norepinephrine increased left ventricular pressure, heart rate, and myocardial O2 consumption rate by approximately 21, 70, and 45%, respectively, and increased epicardial and venous adenosine to 496 +/- 74 and 461 +/- 94 nM, respectively. Log-[ATP]/[ADP][Pi] and [PCr]/[Pi] declined to 4.57 +/- 0.06 and 1.9 +/- 0.3, respectively. Epicardial [AMP] increased from 54 +/- 13 to 123 +/- 24 nM. AMP was not detectable in the venous effluent. Coronary resistance correlated with epicardial and venous [adenosine] (r = 0.86 and 0.90). Epicardial and venous [adenosine] correlated with log[ATP]/[ADP][Pi], [PCr]/[Pi], and cytosolic [AMP]. Hence, interstitial adenosine is linked to cytosolic metabolism and may regulate coronary vascular resistance. Venous adenosine underestimates epicardial adenosine at baseline but more closely approximates epicardial adenosine during norepinephrine infusion.
在31P-核磁共振波谱法监测心肌代谢期间，于基线状态以及用去甲肾上腺素（30 nM）刺激后，检测离体等容豚鼠心脏的心外膜液和冠状动脉流出液中的腺苷释放情况。在基线流量（9.6±0.3 ml·min-1·g-1）时，心外膜和静脉中的腺苷浓度分别为154±40 nM和17±5 nM。磷酸化电位（log[ATP]/[ADP][Pi]）和磷酸肌酸-无机磷酸比率（[PCr]/[Pi]）分别为5.26±0.04和8.5±0.7。去甲肾上腺素使左心室压力、心率和心肌耗氧率分别增加约21%、70%和45%，并使心外膜和静脉中的腺苷分别增加至496±74 nM和461±94 nM。Log-[ATP]/[ADP][Pi]和[PCr]/[Pi]分别降至4.57±0.06和1.9±0.3。心外膜[AMP]从54±13 nM增加至123±24 nM。静脉流出液中未检测到AMP。冠状动脉阻力与心外膜和静脉[腺苷]相关（r = 0.86和0.90）。心外膜和静脉[腺苷]与log[ATP]/[ADP][Pi]、[PCr]/[Pi]和胞质[AMP]相关。因此，间质腺苷与胞质代谢相关，并可能调节冠状动脉血管阻力。静脉腺苷在基线时低估了心外膜腺苷，但在去甲肾上腺素输注期间更接近心外膜腺苷。
