胰岛素对大鼠缺血性海马CA1区神经元的保护作用

Protective effects of insulin on neurons in the ischemic hippocampus CA1 region in rats

目的：探讨胰岛素对海马ＣＡ１区神经元的保护作用．方法：在造成ＳＤ大鼠短暂全脑缺血后即刻、３０ｍｉｎ及１ｈ分别给予１Ｕ／ｋｇ常规胰岛素及２ｇ／ｋｇ２５％葡萄糖液．缺血７ｄ后，取脑固定染色，于前囟后３．８ｍｍ平面对海马ＣＡ１区１ｍｍ长范围内正常神经元进行了计数．结果：假手术组（ｎ＝６）正常神经元计数为１７４．６±１０．７，缺血后即刻（ｎ＝６）及再灌注３０ｍｉｎ给药组（ｎ＝６）正常神经元计数分别为８７．４±４．２，７５．６±５．０．缺血组（ｎ＝６）为１０．２±３．２而再灌注后１ｈ给药组（ｎ＝６）为１２．６±２．２．结论：证实了在全脑缺血后再灌注早期（＜３０ｍｉｎ），给予胰岛素对海马ＣＡ１区神经元具有明显的保护作用．

Objective: To investigate the experimental protective effects of insulin on neurons in ischemic hippocampus CA1 region. Method: The 1 U/kg of insulin and 2 g/kg of 25% solution of glucose were administered to the SD rat intraperitoneally after brain ischemia immediately, 30 min and 1 hour. Seven days after ischemia, the animals were murdered and the brains were fixed and stained for histopathological analysis. Results: The number of neurons (neuronal density, ND) in a 1 mm linear length of hippocampal CA1 region (bregma 3.8 mm) was counted. ND of sham operated group ( n =6) was 174.6±10.7. ND in the ischemic group ( n =6) was 10.2±3.2. ND of groups treated with insulin postischemia immediately ( n =6), 30 min ( n =6) and 1 hour ( n =6) was 87.4±4.2, 75.6±5.0 and 12.6±2.2 respectively. Conclusion: The present study demenstrates that insulin which was given in the early of postischemia (<30 min) has marked protective effects on neurons in hippocampus CA1 region.