高胰岛素血症对大鼠周围神经及髓鞘的影响

Effect of Hyperinsulinemia on Peripheral Nerve and Myelin Sheath in Rats

目的观察高胰岛素血症对大鼠周围神经和髓鞘的影响。方法通过高脂饲料喂养诱导大鼠产生高胰岛素血症,采用行为学方法观察大鼠痛觉敏感性的变化、电镜观察坐骨神经纤维及髓鞘的变化。结果高脂饲料喂养20d后大鼠出现高胰岛素血症,并表现为胰岛素抵抗,但空腹血糖维持正常;28d后大鼠机械刺激痛敏异常,但热刺激痛敏无明显异常,电镜观察显示大鼠坐骨神经有髓纤维病变比例较普通饲料喂养大鼠明显增加。结论周围神经有髓纤维更容易发生病理性损害,高胰岛素血症可能参与了这一病理过程。

Objective To investigate the effect of hyperinsulinemia on peripheral nerve and myelin sheath in rats.Methods Hyperinsulinemia were induced by feeding rats with high-fat diet,algesthesia was determined by ethology approach,sciatic nerve fibers and myelin sheath were observed through electron microscope.Results Rats were fed with high-fat diet for 20 days and showed hyperinsulinemia,characterized by insulin resistance and normal fasting blood glucose.Twenty-eight days later,abnormal Paw Withdrawal Mechanical Threshold(PWMT)appeared and paw withdrawal thermal latency(PWTL)maintained as normal.Under electron microscope,the lesion proportion of rat sciatic nerve myelinated fibers was obviously more than that of rats fed with common diet.ConclusionIn this process,peripheral nerve myelinated fibers damage is more likely to occur,and hyperinsulinemia may be involved.