高血糖对大鼠骨骼肌钙负载和cAMP含量的影响

The effects of hyperglycemia on calcium load and cyclic AMP content in rat skeletal muscle

目的 探讨高浓度葡萄糖对正常和糖尿病大鼠骨骼肌钙负载和环磷酸腺苷 (c AMP)含量的影响。方法 体内实验直接测定糖尿病和正常大鼠骨骼肌钙负载和 c AMP含量 ,体外实验用比目鱼肌与 5 .6 mmol/ L和 16 .7mmol/ L葡萄糖保温后测定钙负载和 c AMP,二者分别采用原子光谱吸收法和放免法测定。结果 高血糖对骨骼肌具有升高c AMP、降低钙负载的作用。糖尿病本身可升高 c AMP,并且高血糖是升 c AMP必要的辅助因素 ;同时糖尿病倾向于阻碍高血糖引起的钙负载下降。结论 高血糖对大鼠骨骼肌钙负载和 c AMP含量的影响与其抗胰岛素作用相一致 。

Objective To investigate the effect of hyperglycemia on calcium load and cyclic AMP content in normal and STZ diabetic rat skeletal muscle.Methods Calcium load and cyclic AMP content were measured in vivo and in vitro after incubation with 5.6mmol/L and 16.7mmol/L glucose concentration.Atom spectrum absorption assay for calcium and radioimmunoassay for cAMP were employed.Results High concentration glucose elevated cyclic AMP content and lessened calcium load significantly.Cyclic AMP also elevated in diabetic skeletal muscle incubated with even 5.6mmol/L glucose.Diabetes was necessary for high concentration glucose to elevate cyclic AMP in vitro,because cyclic AMP did not change in normal rat muscle even incubated with 16.7mmol/L glucose.But diabetes discounted the reduction of calcium load induced by 16.7mmol/L glucose.Conclusion The effects of hyperglycemia on calcium load and cyclic AMP content in skeletal muscle may accord with its anti insulin action,which may be involved in the mechanism of glucose toxicity.