myocardial interstitial serotonin and 5-hydroxyindole acetic acid levels during ischemia-reperfusion

采用微透析技术，用单胺氧化酶(MAO)、5-HIAA法检测麻醉大鼠和兔缺血再灌注区心肌间质5-羟色胺及其代谢物的含量。在载体中，缺血时5-羟色胺水平升高，而5-HIAA水平下降。再灌流后，5-羟色胺水平一过性升高，然后下降。再灌注后5-HIAA水平升高，并维持在较高水平。氟西汀可降低缺血时5-羟色胺的水平，但不改变再灌流后的5-HIAA水平。Pargyline再灌流后升高5-羟色胺水平，降低再灌流后5-HIAA水平。缺血时，载体介导的5-羟色胺外流可导致5-羟色胺水平升高，而5-HIAA水平的降低可归因于缺氧和酸中毒引起的MAO活性降低。再灌注后血中5-羟色胺的清除和摄取载体的清除可能是5-羟色胺水平降低的原因之一。

Using microdialysis technique, we monitored myocardial interstitial 5-HT and its metabolite by monoamine oxidase (MAO), 5-HIAA levels in the ischemic region of anesthetized rat or rabbit during ischemia and reperfusion. In vehicle, 5-HT levels increased during ischemia, but 5-HIAA levels decreased during ischemia. After reperfusion 5-HT levels transiently increased and then declined. 5-HIAA levels increased after reperfusion and kept high level. Fluoxetine decreased 5-HT levels during ischemia, but did not change 5-HIAA levels after reperfusion. Pargyline increased 5-HT levels after reperfusion and decreased 5-HIAA levels after reperfusion. During ischemia, the carrier-mediated 5-HT efflux could contribute to the increase in 5-HT levels and the decrease in 5-HIAA levels could be ascribed to the reduction of MAO activity due to oxygen depletion and acidosis. After reperfusion, washout to blood as well as removal by uptake carrier could contribute to the decrease in 5-HT levels.