L-精氨酸对模拟缺血再灌注培养乳兔窦房结细胞损伤的影响

目的:观察模拟缺血再灌注(IR)培养乳兔窦房结细胞(SANC)损伤及左旋精氨酸(L-Arg)干预作用。方法:对SANC模拟低糖缺氧培养,添加L-Arg和L-Arg L-NAME与培养细胞共同孵育,观察细胞形态变化。细胞分为7组:正常对照组;I120组;I120R120组;I120 L-Arg组;I120R120 L-Arg组;I120 L-Arg L-NAME组;I120R120 L-Arg L-NAME组。结果:I120组、I120 L-Arg L-NAME组较多细胞核浓缩,胞质嗜酸性增强为紫红色;AO荧光染色示凋亡细胞体积明显缩小,核呈黄绿色,断裂为多个碎块状,碎裂的核由膜包裹着凸起于细胞表面呈黄绿色凋亡小体,与I120组、I120R120组比较,I120 L-Arg组、I120R120 L-Arg组凋亡率明显降低(P<0.05);而I120 L-Arg L-NAME组和I120R120 L-Arg L-NAME组无明显改善(P>0.05);电镜下,凋亡细胞核染色质固缩,聚集于核膜呈境界分明的块状或新月形小体,染色质凝聚于核周边;细胞核分解成大小不等的浓缩团块,游离于胞浆中。结论:①模拟缺血一定时间后可以诱导SANC凋亡,再灌注后细胞损伤加重;②NO底物L-精氨酸可减轻模拟缺血-再灌注窦房结细胞结构损伤。

The effect of L-Arginine on damnification of cultured sino-atrial node cells from neonatal rabbits simulating ischemia reperfusion

Objective:To observe the damnification of cultured SAN cells after simulating I/R and the role of L-Arginine for this process. Methods:By simulating ischemia-reperfusion condition,SAN cells were cultured with low carbohydrate and hypoxygenation and analyzed. 7 groups were arranged as:control group,I120 group,I120R120 group,I120 L-Arg group,I120R120 L-Arg group,I120 L-Arg L-NAME group and I120R120 L-Arg L- NAME group. Results:In group I120 and group I120 L-Arg L-NAME,karyon condensed obviously,and cytoplasm was stained as amaranth. AO-fluorescence staining showed that apoptotic cells dwindled,and karyon broke into many small bits,which was enwrapped by membrane and heaved on the surface. Chromatin of apoptotic karyon condensed and conglomerated below the karyotheca,even decompounded into mass or crescent-shaped pieces and dissociated among the cytoplast. AI of sino-atrial node cells of I120 L-Arg group and I120R120 L-Arg group decreased significantly comparing with that of I120 group and I120R120 group (P<0.05),but there were no significant difference between I120 L-Arg L-NAME group and I120R120 L-Arg L-NAME group(P>0.05). Conclusions:SAN cells undergoing simulating ischemia-reperfusion are damaged heavily with the time of I/R. L-Arginine can inhibit apoptosis in this pathological process.