Grover G J, Talafih K, Weiss H R
Eur J Pharmacol. 1985 Jan 15;108(1):9-18. doi: 10.1016/0014-2999(85)90277-8.
The purpose of this study was to determine the effect of graded doses of norepinephrine on the regional O2 supply/consumption ratio in ischemic rabbit hearts. Open chested, anesthetized rabbits were used and regional flows, O2 extraction, consumption and O2 supply/consumption ratios were determined before and 1 h after occlusion of the left anterior descending coronary artery in controls and animals given 0.1, 1.0 and 10 micrograms/kg per min norepinephrine (NE). After occlusion in controls, mean myocardial blood flow decreased 40% in the occluded region. Blood flow was also depressed in the occluded region for all NE doses compared to their own preocclusion values, but was higher in these regions compared to control animals. O2 extraction was higher in the occluded region compared to the nonoccluded region for all groups; however these values were lower in the NE groups compared to controls. NE increased O2 consumption in the occluded and nonoccluded regions compared to control group values. The O2 supply/consumption ratio was depressed in the occluded region in all groups compared to the nonoccluded region, though no differences were seen between NE and control groups. Thus, increases in the blood flow to the occluded region were proportional to the increases in O2 consumption with infusion of NE, indicating that a reserve exists and can be utilized with NE.
本研究的目的是确定不同剂量去甲肾上腺素对缺血兔心脏局部氧供/氧耗比的影响。使用开胸、麻醉的兔子，在对照组以及给予每分钟0.1、1.0和10微克/千克去甲肾上腺素（NE）的动物中，在左冠状动脉前降支闭塞前和闭塞后1小时测定局部血流量、氧摄取、氧耗及氧供/氧耗比。在对照组中，闭塞后闭塞区域的平均心肌血流量下降了40%。与各自闭塞前的值相比，所有NE剂量组闭塞区域的血流量也有所降低，但与对照组动物相比，这些区域的血流量更高。所有组中，闭塞区域的氧摄取均高于非闭塞区域；然而，与对照组相比，NE组的这些值较低。与对照组相比，NE增加了闭塞区域和非闭塞区域的氧耗。与非闭塞区域相比，所有组闭塞区域的氧供/氧耗比均降低，尽管NE组与对照组之间未见差异。因此，随着NE输注，闭塞区域血流量的增加与氧耗的增加成正比，表明存在储备且可通过NE加以利用。
