Cellular mechanisms of contractile and vasodilating actions of anesthetics in vascular smooth muscle

目的：研究血管紧张素II(AII)和血管加压素(VP)对人离体胃粘膜动脉的直接收缩作用及其联合作用。结论：小剂量VP和AII对人离体动脉的收缩作用有很强的协同作用。此外，出血时血浆AII和VP水平的升高表明，这种协同作用可能在优化血管收缩和在危重状态下维持血压方面具有重要的生理和临床意义。第二年；目的：关于超声刀骨架化对胸内动脉(ITA)和胃网膜动脉(GEA)血管功能的影响的数据很少。结论：超声刀完全骨化可保留骨化移植物的平滑肌功能，而超声骨化移植物的内皮功能可能会明显受损。目的：在血管紧张素II(AII)的直接收缩作用中，该肽引起强烈的快速反应，从而在短时间内使收缩性能下降。因此，本研究的目的是确定AII诱导的人血管平滑肌(如胃网膜动脉)发生快速反应的机制。结论：AII释放的血管扩张剂前列腺素有可能参与人类所有的心动过速反应，因为吲哚美辛预处理可减少但不能消除心动过速反应。

First year; Objective: To determine the direct contractile effects of angiotensin II (AII)and vasopressin (VP), and the effects of combinations of these agonists, in human isolated gastroepiploic arteries in vitro. Conclusion: There is a powerful synergism between the contractile effects of low-dose VP and AII in this human isolated artery. Moreover, the elevations of plasma AII and VP levels during hemorrhage suggest that this synergism may be both physiologically and clinically important in optimizing vasoconstriction and maintaining blood pressure in such critical states.Second year; Objective: There are few data available on the effect of ultrasonic skeletonization with the harmonic scalpel on internal thoracic artery (ITA)and gastroepiploic artery (GEA) vessel function. Conclusion: Ultrasonic complete skeletonization with the harmonic scalpel may retain smooth muscle function of skeletonized grafts, whereas endothelial function of ultrasonic skeletonized grafts may be significantly compromised.Third year; Objective; In the direct contractile effects of angiotensin II (AII), this peptide induced strong tachyphylaxis, and thus the contractile performance were degraded in a short time. Therefore, the aim of this study is to determine the mechanisms responsible for the AII-induced tachyphylaxis in human vascular smooth muscle, such as a gastroepiploic arteries. Conclusion; There is a possibility that vasodilator prostaglandins, which are released by AII, are involved in AII tachyphylaxis in humans, since pretreatment with indomethacin reduces, but dose not abolish, the tachyphylaxis