Knabb R M, Gidday J M, Ely S W, Rubio R, Berne R M
Am J Physiol. 1984 Nov;247(5 Pt 2):H804-10. doi: 10.1152/ajpheart.1984.247.5.H804.
Dipyridamole, a vasodilator that potentiates the actions of exogenous adenosine, is known to inhibit cellular uptake of adenosine, but its effects on cellular adenosine release, and thus interstitial adenosine levels, are disputed. We used the accumulation of adenosine in pericardial infusates (PCI) as an index of interstitial adenosine concentration and observed the effects of dipyridamole on relationships among coronary blood flow (CBF), myocardial oxygen consumption (MVO2), and PCI adenosine concentrations during steady-state alterations of cardiac work. Dipyridamole increased CBF and PCI adenosine concentration without altering MVO2. The relationship between PCI adenosine and CBF was unaltered, supporting a cause and effect relationship between interstitial adenosine concentration and CBF. In addition, we determined that unlike previous studies in isolated perfused hearts the washout of adenosine by coronary plasma was unaffected by dipyridamole. The results support previous suggestions that, whereas dipyridamole inhibits adenosine uptake, it does not alter cellular adenosine release, and therefore interstitial adenosine levels are increased. The constant relationship between PCI adenosine and CBF supports hypotheses that attribute the hyperemias associated with increased cardiac work or with dipyridamole to increased interstitial adenosine.
双嘧达莫是一种血管扩张剂，可增强外源性腺苷的作用，已知它能抑制细胞对腺苷的摄取，但其对细胞腺苷释放以及间质腺苷水平的影响存在争议。我们将心包灌注液中腺苷的蓄积量（PCI）作为间质腺苷浓度的指标，并观察了双嘧达莫在心脏工作稳态改变期间对冠状动脉血流量（CBF）、心肌耗氧量（MVO2）和PCI腺苷浓度之间关系的影响。双嘧达莫增加了CBF和PCI腺苷浓度，而未改变MVO2。PCI腺苷与CBF之间的关系未改变，支持了间质腺苷浓度与CBF之间的因果关系。此外，我们确定，与先前在离体灌注心脏中的研究不同，冠状动脉血浆对腺苷的清除不受双嘧达莫影响。这些结果支持了先前的观点，即双嘧达莫虽然抑制腺苷摄取，但不改变细胞腺苷释放，因此间质腺苷水平会升高。PCI腺苷与CBF之间的恒定关系支持了这样的假设，即将与心脏工作增加或双嘧达莫相关的充血归因于间质腺苷增加。
