Law W R, McLane M P, Raymond R M
Department of Surgery, Loyola University, Stritch School of Medicine, Maywood, Illinois.
Diabetes. 1988 Jun;37(6):842-5. doi: 10.2337/diab.37.6.842.
The adenosine-receptor antagonist 8-phenyltheophylline (8-PTH) was used to study the role of endogenous adenosine in modulating insulin-stimulated myocardial glucose uptake (MGU) in vivo. Dogs were surgically instrumented under pentobarbital sodium anesthesia to measure hemodynamics and obtain blood samples for determinations of oxygen and glucose concentrations. Myocardial uptake of these substances was calculated as the product of the appropriate arterial-coronary sinus differences and circumflex blood flow. The response to insulin was determined with the hyperinsulinemic-euglycemic clamp technique. During insulin infusion, MGU increased from 3.12 +/- 0.8 to 9.20 +/- 1.8 mg/min (mean +/- SE). In contrast, insulin failed to increase MGU when 8-PTH was being infused into the circumflex artery. These results demonstrate that some degree of adenosine-receptor-mediated activity is required for insulin to stimulate myocardial glucose uptake. It is suggested that the presence of adenosine at its receptor may be an important factor during conditions in which myocardial insulin resistance may develop.
腺苷受体拮抗剂8-苯基茶碱（8-PTH）被用于研究内源性腺苷在体内调节胰岛素刺激的心肌葡萄糖摄取（MGU）中的作用。在戊巴比妥钠麻醉下对犬进行手术插管，以测量血流动力学并采集血样用于测定氧气和葡萄糖浓度。这些物质的心肌摄取量通过适当的动脉-冠状窦差值与回旋支血流量的乘积来计算。采用高胰岛素-正常血糖钳夹技术测定对胰岛素的反应。在输注胰岛素期间，MGU从3.12±0.8增加至9.20±1.8mg/min（平均值±标准误）。相比之下，当向回旋支动脉输注8-PTH时，胰岛素未能增加MGU。这些结果表明，胰岛素刺激心肌葡萄糖摄取需要一定程度的腺苷受体介导的活性。提示在可能发生心肌胰岛素抵抗的情况下，腺苷在其受体处的存在可能是一个重要因素。
