间断性人工重力对模拟失重大鼠颈总动脉平滑肌细胞凋亡的影响

目的:研究3周模拟失重大鼠颈总动脉平滑肌细胞凋亡的变化及间断性人工重力对其的影响。方法:以尾部悬吊大鼠(SUS)模拟失重,同期每天悬吊23h、站立1h(STD)模拟间断性人工重力的对抗效果,用M30染色及Tunel染色方法观察3周SUS组、同步对照(CON)组及STD组颈总动脉平滑肌细胞早期和中晚期的凋亡情况,并用免疫组织化学方法及Western blot印迹方法观察各组大鼠颈总动脉组织Caspase-3的蛋白表达变化。结果:与CON组比较,SUS组大鼠颈总动脉平滑肌细胞M30染色阳性细胞明显减少,STD组M30染色阳性细胞较CON组及SUS组显著增加;SUS组Tunel染色阳性细胞较CON组及STD组显著减少,STD组Tunel染色阳性细胞较CON组及SUS组显著增加;SUS组Caspase-3的表达较CON组显著降低(P<0.05),STD组Caspase-3的表达较CON组及SUS组显著增高(P<0.01)。结论:模拟失重可引起大鼠颈总动脉平滑肌细胞凋亡减少,每日1 h的-Gx对抗使颈总动脉的凋亡增加。Caspase-3可能在调控模拟失重所致血管组织平滑肌细胞的凋亡中发挥作用。

Effects of Intermittent Artificial Gravity on Apoptosis of Common CarotidSmooth Muscle Cells in Simulated Microgravity Rats

Objective: To investigate the effects of 3 weeks simulated microgravity and intermittent artificial gravity on apoptosis of common carotid smooth muscle cells(CCSMCs) in rats.Methods: Tail-suspension rats(SUS) were used to simulate the effects of microgravity,and homochronous countermeasure standing(STD,daily 1 h of-Gx gravitation) was used to simulate the effects of intermittent artificial gravity(IAG).The apoptosis of CCSMCs was assessed by the basis of M30 CytoDEATH Fluorescein(M30)and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(Tunel) staining.The protein expression of Caspase-3 in common carotid was demonstrated by Immunohistochemistry and Western blot.Results: After 3-week simulated microgravity and intermittent artificial gravity,compared with CON,M30 and TUNEL positive CCSMCs in SUS rats decreased significantly,while M30 and TUNEL positive CCSMCs increased significantly in STD;Compared with SUS,M30 and TUNEL positive CCSMCs in STD rats increased significantly.Compared with CON and STD,the expressions of Caspase-3 decreased significantly(P < 0.01 respectively) in SUS,and compared with CON and SUS,the expression of Caspase-3 increased significantly(P < 0.01 respectively) in STD.Conclusions: The decrease of apoptosis CCSMCs can be induced by simulated microgravity,while intermittent artificial gravity can cause the increase of apoptosis CCSMCs.These findings further suggest that the expression of Caspase-3 may mediate the alteration in apoptosis of CCSMCs induced by microgravity or intermittent artificial gravity(IAG).