The roles of sex hormone and gender difference for spinal cord protection in spinal cord ischemia

本文测定了兔主动脉阻断和开放后脊髓组织氧分压(PsptO2)的变化，阐明了远端缺血预适应(RIPC)和静脉注射雌激素改善脊髓缺血后PsptO2的机制。在异氟醚麻醉的兔(n=36)上，我们准备用组织PO2监测主动脉阻断后的PsptO2。在第一组实验中，我们将18只动物分为3组，(A)对照组，(B)RIPC组，n=6，(C)格列本脲(0。在第二组实验中，我们还将18只动物分成3组，(D)对照组，(E)雌激素组(17ss雌二醇：20μg)，n=6，(F)福维斯特(1 mg/kg)组，n=6。RIPC改善主动脉阻断后20min、开放后0、2、5min的PsptO2。格列本脲对上述指标的改善作用减弱。17S雌二醇可改善主动脉阻断后20min和开放后0、2、5min PsptO2的变化。结论：主动脉阻断后，RIPC通过激活KATP通道改善PsptO2的恶化，17ss雌二醇通过雌激素受体激活改善PsptO2的恶化。

We evaluated the tissue oxygen partial pressure of spinal cord(PsptO2) following aortic cross-clamping and-unclamping, and then clarified the mechanism of improvement in the PsptO2 following spinal ischemia observed with remote ischemic preconditioning(RIPC) or intravenous estrogen in rabbits. In isoflurane anesthetized rabbits(n=36), we prepared for measurement of PsptO2 following aortic cross-clamping using tissue PO2 monitoring. In the first set of experiment, we allocated 18 animals into 3 groups,(a) control group ; n=6,(b) RIPC group ; n=6,(c) glibenclamide pretreatment(0. 3mg/kg) group ; n=6. In the second set of experiment, we also allocated 18 animals into 3 groups,(d) control group ; n=6,(e) estrogen(17ss estradiol : 20μg) group ; n=6,(f) fulvestrant pretreatment(1mg/kg) group ; n=6. RIPC improved deterioration of the values in PsptO2 at 20 min after aortic cross-clamping and 0, 2, 5 min after aortic unclamp. The improvement was diminished by pretreatment of glibenclamide. Administration of 17s estradiol improved deterioration of the values in PsptO2 at 20 min after aortic cross-clamping and 0, 2, 5 min after aortic unclamp. The improvement was diminished by pretreatment of fulvestrant.In conclusion, after aortic cross-clamping, the RIPC performed improves the deterioration in PsptO2 through the KATP channel activation and 17ss estradiol improves the deterioration in PsptO2 through the estrogen receptor activation.