Lipasti J, Nevalainen T J, Alanen K
Exp Pathol. 1981;20(2):73-8. doi: 10.1016/s0232-1513(81)80014-x.
The effect of hypoxia on the microvascular function in continuously perfused isolated rat hearts was studied. The development of hypoxic contracture was determined by measuring the left ventricular pressure or the decrease of the left ventricular volume. The myocardial perfusability was tested by infusing 0.1 percent sodium fluorescein in isotonic saline into the cannulated aortic root at 0, 15, 30, 60 and 90 minutes of hypoxic glucose-free buffer perfusion. The percentage perfused with the fluorescent tracer in horizontal frozen myocardial sections was estimated by point counting from colour photographs taken under ultraviolet light. The coronary flow was estimated by measuring the flow of the perfusate through the vasculature under constant perfusion pressure. The hypoxic contracture was completed in 25 minutes in which time the coronary flow decreased gradually by 50 percent and thereafter the flow remained constant. The myocardium was fully perfused in controls and at 0 minutes of hypoxic glucose-free perfusion. There was an abrupt decrease in the perfusability between 15 and 30 minutes from 99 percent to 58 percent, respectively. At 60 and 90 minutes 65 percent of the myocardium were still perfused. It was concluded that the myocardial perfusability decreases when the left ventricular contracture develops during hypoxic perfusion.
研究了缺氧对持续灌注的离体大鼠心脏微血管功能的影响。通过测量左心室压力或左心室容积的减少来确定缺氧性挛缩的发展。在无葡萄糖缓冲液缺氧灌注0、15、30、60和90分钟时，将0.1%的荧光素钠等渗盐水注入插管的主动脉根部，以测试心肌灌注能力。通过对在紫外线下拍摄的彩色照片进行点计数，估算水平冷冻心肌切片中被荧光示踪剂灌注的百分比。通过在恒定灌注压力下测量灌注液通过血管系统的流量来估算冠状动脉血流量。缺氧性挛缩在25分钟内完成，在此期间冠状动脉血流量逐渐减少50%，此后流量保持恒定。在对照组和无葡萄糖缺氧灌注0分钟时，心肌得到充分灌注。在15至30分钟之间，灌注能力分别从99%急剧下降到58%。在60和90分钟时，仍有65%的心肌被灌注。得出的结论是，在缺氧灌注期间左心室挛缩发展时，心肌灌注能力降低。
