血流动力学改变对猫蓝斑核儿茶酚胺类神经递质释放的影响

Effects of Experimentally-induced Changes in Hemodynamics on Catecholamines Release in the Locus Coeruleus

应用推－挽灌流方法，研究麻醉猫蓝斑核儿茶酚胺类神经递质去甲肾上腺素（ＮＡ）和多巴胺的释放，观察实验性地改变猫血流动力学时对以上递质释放的影响。结果发现，血容量增加３０％、血压上升２．４ｋＰａ时，或静脉注射ＮＡ、血压上升８ｋＰａ时，蓝斑核内源性ＮＡ释放明显减少；另一方面，血容量减少１５％、血压下降５．６ｋＰａ时，ＮＡ的释放增加１倍，而静脉注射硝普纳、血压下降８．７ｋＰａ时，ＮＡ的释放无明显改变。在以上各实验条件下引起的血流动力学改变，对猫蓝斑核内源性多巴胺的释放均无明显影响。

By using push-pull superfusion technique the release of catecholamines(noradrenaline,dopamine) was studied in the locus coeruletis of the anaesthetized cats.The effects of experimentally induced changes in hemodynamics on catecholamines release were also investigated.The results showed that the rise in blood pressure(8 kPa) elicited by increased Hood volume(30%) was associated with a decrease of noradreneline,and intravenous infusion of noradreneline elicited a pronounced pressor response which was also associated with a decrease in the release of noradrenaline in the locus coeruleus.On the contrary,a drop of blood pressure(5.6 kPa) caused by hypovolaemia(15%) enhanced noradrenaline release by one-fold,but lowering of blood pressure by vasodilation showed no effect.