尾吊对大鼠离体肺循环的影响及NOS抑制剂的对抗作用

Effects of Tail-suspension and NOS Inhibitor on Pulmonary Circulation of Isolated Rats' Lungs

目的研究尾吊模拟失重对大鼠离体肺循环的影响和NOS抑制剂的对抗作用,为模拟失重对肺循环局部调节和立位耐力和运动能力降低机制研究积累资料。方法 -30°尾吊(TS)模拟失重的生理效应,Wistar雄性大鼠被随机分成3组:对照组(Con,n=8)、7 d尾吊组(TS7,n=10)和14 d尾吊组(TS14,n=11)。在人工胸腔内,采用离体肺灌流技术,超声流量计和恒流蠕动泵将肺循环流量控制在13.58 mL/min。PowerLab/4SP生理记录系统检测模拟失重对大鼠最大肺动脉压、静脉压和阻力影响和10-5 mol/L L-NAME的对抗作用。结果 TS7,TS14组大鼠离体灌流的肺动脉压最大值显著降低(P<0.01),肺动脉端阻力和肺循环阻力显著降低(P<0.01),10-5 mol/L L-NAME能较好对抗模拟失重对肺循环的影响。结论 NOS抑制剂对抗立位耐力和运动能力降低有应用前景。

Objective To study the effects of simulated weightlessness with tail-suspension（TS） and NOS（Nω-nitro-L-arginine methylester） inhibitor on the pulmonary circulation of isolated lung perfusion in rats,so that to gather data for researches on mechanism of local regulation of pulmonary circulation and mechanism of orthostatic intolerance and the decrease of exercise capability.Methods Tail-suspended rats at-30° were used as the model to simulate the physiological effects of weightlessness.Wistar rats were randomly arranged into control group（Con,n=8）,7-day TS group（TS7,n=10） and group 14-day TS（TS14,n=11）.With the isolated lung perfusion technique in artificial thorax,the pulmonary arterial volume controlled with the Transonic Systems and the constant peristaltic pump at 13.58 mL/min.The pressure of pulmonary arteries,veins and resistance were measured with a PowerLab/4SP physiological system,and estimated the effects of NOS Inhibitor.Results The maximal pulmonary arterial pressure,the resistance of pulmonary arteries and pulmonary circulation decreased significantly（P0.01） in the TS7 and TS14 rats.The 10-5 mol/L L-NAME could ameliorate these changes of pulmonary circulation.Conclusion NOS inhibitor may have some foreground in alleviating the orthostatic intolerance and the decrease of exercise capability.