孕酮对大鼠创伤性脑损伤保护作用

目的 探讨孕酮(progesterone,PROG)对大鼠创伤性脑损伤(TBI)后皮质诱导型一氧化氮合酶(iNOS)和凋亡蛋白酶(caspase-3)表达影响。方法 将健康雄性SD大鼠随机分为假手术组、脑损伤组、孕酮治疗组。按照改进的Feeney自由落体损伤装置制作大鼠脑损伤模型。于伤后不同时间取材,采用免疫组织化学法,检测大鼠脑组织中iNOS和caspase-3表达水平。结果 孕酮治疗组iNOS和caspase-3伤后6,24,48,72 h的表达水平分别为(11.62±1.52),(21.38±1.41),(12.94±2.73),(9.42±1.71)和(12.27±1.35),(20.57±2.92),(16.54±1.45),(10.47±1.39),与脑损伤组比较明显降低,差异有统计学意义(P<0.05)。结论 孕酮可能通过抑制脑损伤后iNOS的活性,下调caspase-3的表达,起到对脑的保护作用。

Neuroprotective effect and its mechanism of progesterone on neurons after traumatic brain injury in rats

Objective To investigate the effect of proge sterone(PROG)on the expression of inducible nitric oxide synthase(NiOS)and caspase-3 in the cortex after traumatic brain injury(TBI)and to study the neuro protective effects and molecular mechanism of progesterone on TBI in rats.Methods Healthy male Spraque Dawley rats were divided at random into three groups:false operative group,TBI group and PROG treated group.The TBI of rats was duplicated with the miproved Feeneys method.The rats in the three groups were killed at 6,24,48,72,and 144 hours after the injury.The expression of iNOS and caspase-3 were examined by mimunohistochem istry.Results At the time of 6,24,48,and 72 hours after the injury,the expression of NiOS and caspase 3 in the PROG treated group were 11.62±1.52,21.38±1.41,12.94±2.73,9.42±1.71,and 12.27±1.35,20.57±2.92,16.54±1.45,10.47±1.39,respectively,and were distinctly less than those of the TBI group(18.24±1.93,43.17±3.58,20.13±3.81,13.82±2.56,and 24.56±2.71,38.23± 3.36,27.83±2.68,14.23±2.83).There were significant differences between the TBI group and the PROG treated group in the number of NiOS and caspase-3 positive cells at 6,24,48,and 72 hours after injury(P<0.05 for all).Conclusion PROG has protective effect on TBI that may relate to inhibition of NiOS activity,down regutation of caspase 3 expression.