镁离子对腺苷酸环化酶-环磷酸腺苷系统功能的调整作用

Modulation effect of magnesium ion on the adenyl cyclase-cAMP system function

由家兔耳静脉注入超生理阈值水平的去甲肾上腺素(NE)50ug/kg体重〔NE含于5ml生理盐水(NS)内,1ml/min〕,经10min后处死,取左室肌进行生化分析,结果显示环磷酸腺苷(cAMP)含量明显升高,表明心肌细胞膜的结构和功能遭受明显的损害,与对照组(只注射NS 5ml/5min)比较具有显著性统计学差异.我们采用镁制剂进行了实验研究,在输注NE前10min,经耳静脉注入硫酸镁200mg/kg体重(含于5mlNS内,1ml/min),结果显示NE的损害效应明显减轻,镁的拮抗能力在50%～80%幅度,与NE组比较,有显著性统计学差异,表明镁对心肌细胞膜结构和功能具有可靠的保护作用,对NE引起心肌细胞损害的毒性具有强力拮抗作用.

In the present study we investigated the antagonistic effects of magnesium (Mg) on the increased myocardial cAMP level induced by norepinephrine 50 μg/kg infused through ear vein during 5 min in rabbits. Infusing of MgSO4 200mg/kg into ear vein in a duration of 5 min before 10 min of NE infusion may prevent cAMP level raise in myocardium from NE infusion effectively. It indicated that Mg2+ might be able to protect heart from the NE injury and hence might be used in clinical for treatment of cardiovascular diseases and for catecholamine cardiomyopathy in particular.