胰岛素对正常大鼠主动脉血红素氧合酶-CO-cGMP系统活性的影响

EFFECT OF INSULIN ON HEME OXYGENASE-CARBON MONOXIDE-CYCLIC GUANOSINEMONOPHOSPHATE SYSTEM IN RAT AORTA

目的 :通过观察生理范围不同浓度胰岛素对Wistar大鼠主动脉血红素氧合酶 一氧化碳 环磷酸鸟苷 (HO CO cGMP)系统活性的影响 ,以探讨胰岛素与血管舒缩功能的关系。方法 :应用离体Wistar大鼠主动脉组织孵育技术和主动脉平滑肌细胞培养技术 ,以胆红素生成量作为HO活性的指标 ,以培养上清液中碳氧血红蛋白 (COHb)含量作为内源性CO产量的指标 ,应用放射免疫法测定主动脉环磷酸乌苷含量 ,从组织和细胞水平观察生理范围内不同浓度胰岛素对血管局部HO活性 ,内源性CO产生量和环磷酸鸟苷的影响。结果 :生理范围不同浓度胰岛素 (0 .0 4、0 .0 8、0 .16mU/L)使主动脉HO活性分别增高 48.2 %、6 0 .8%、80 .7% ;使主动脉血管平滑肌细胞培养上清中CO Hb含量增高 8.7%、17.4%、39.1% ;使cGMP含量增加 96 .6 % ,197.1% ,130 .7%。结论 :生理浓度胰岛素对正常大鼠血管局部血红素 HO CO cGMP系统活性存在浓度依赖的增强作用。提示在胰岛素引起的血管舒张和低血压中 ,可能涉及血管局部的HO CO cGMP系统的激活。

Aim:To investigate the effect of insulin on the HO-CO-cGMP system.Methods:①Isolated wistar rat aortas were cultured in the media containing different concentration insulin (0.04 mU/L,0.08 mU/L,0.16 mU/L) for 24 hours.The relative activity of HO was measured with the bilirubin (pmol/g/h).②The wistar rat aortic smooth muscle cells were cultured in the solution containing insulin (consistency same above) for 24 hours.The relative amounts of carbon monoxide released into the media were measured with the quantifying carbon monoxide hemoglobin (COHb).③Isolated rat aortas were cultured in the media containing different concentration insulin (consistency same above) for 24 hours.The cGMP content in the tissue of aorta were measured by radioimmunitic method.Resultes:In the condition of insulin presenced in the solution (consistency as above:0.04 mU/L,0.08 mU/L and 0.16 mU/L):①The HO activities in the aorta were increased to 48.2%,60.8% and 80.7%,respectively (vs control, P <0.01).②The COHb in the culture solution of VSMCs were increased to 8.7%,17.4%,39.1%,respectively(vs control, P <0.05 or P <0.01).③The cGMP content in the tissue of aortas were increased to 96.6%,197.1% and 130.7% respectively (vs control P <0.01).Conclusion:This study suggests that the insulin may activate the HO-CO-cGMP system in Wistar rat aorta.This may be one of the mechanisms by which insulin causes vasodilation.