Overholser K A, Harris T R
J Pharmacol Exp Ther. 1984 Apr;229(1):148-53.
The effects of adenosine on capillary-tissue exchange have not been evaluated. Although adenosine is a known vasodilator, its effects on nutritive flow are unknown. We therefore measured the influence of adenosine on resistance and capillary exchange in normal and mildly ischemic myocardium in 11 anesthetized, heparinized dogs. Flow to the left anterior descending artery was measured and controlled through an extracorporeal shunt from the carotid artery. Capillary permeability-surface area for sucrose (PS) was determined using the multiple-tracer technique in which mixtures of isotopes were injected into the coronary arterial shunt. We found that in the normal myocardium, intracoronary infusion of adenosine at 8 +/- 2 (S.E.M.) micrograms/ml of plasma significantly lowered resistance and increased PS. In the ischemic myocardium, however, large doses of adenosine (200 +/- micrograms/ml of plasma) lowered resistance but failed to increase PS. We interpret these results to mean that in mild, flow-reduction ischemia, adenosine did not lead to a recovery of capillary surface area for exchange, but simply increased flow through capillaries which had already been functioning. Nutritional flow was not enhanced.
腺苷对毛细血管 - 组织交换的影响尚未得到评估。尽管腺苷是一种已知的血管扩张剂，但其对营养性血流的影响尚不清楚。因此，我们在11只麻醉、肝素化的犬身上测量了腺苷对正常和轻度缺血心肌中阻力和毛细血管交换的影响。通过颈动脉体外分流测量并控制左前降支动脉的血流。使用多示踪技术测定蔗糖的毛细血管通透性 - 表面积（PS），即将同位素混合物注入冠状动脉分流中。我们发现，在正常心肌中，以8±2（标准误）微克/毫升血浆的浓度冠状动脉内输注腺苷可显著降低阻力并增加PS。然而，在缺血心肌中，大剂量腺苷（200±微克/毫升血浆）可降低阻力，但未能增加PS。我们将这些结果解释为，在轻度、血流减少的缺血中，腺苷并未导致用于交换的毛细血管表面积恢复，而只是增加了已经在发挥功能的毛细血管中的血流。营养性血流并未增强。
