医药学论文：高温联合辐射对胚胎神经发育及脑热应激蛋白的影响

【关键词】 高温；辐射；孕鼠胚胎；神经发育；脑热应激蛋白质
【关键词】 高温；辐射；孕鼠胚胎；神经发育；脑热应激蛋白质
【Abstract】 Objective To explore the relation between the embryonic nervous development induced by hyperthermia combined with radiation and early embryonic brain proteins or HSPs'' expression. Methods 130 pregnant mice were randomly divided into 13 groups( each n= 13).On the 8th and 9th day of pregnance, the mice received one time of general irradiation of 60Co and γray respectively, the dosage of irradiation was 1.0 Gy;on the 10th day ,the mice were put in hotboxes keeping their rectal temperature at 37±0.5℃, 41±0.5℃ and 42±℃0.5℃ persisting for 3,4 and 5 mins, respectively. After two hours of the mice leaveing warming boxes, 5 mice randomly selected from each group per timesection were executed by cervical vertebra luxation. The HSP70 of embryonic brain, protein content and deformations of embryonic nervous systems were quantitatively analyzed with the Western dot blot and Lowry method. Results The toxicity of hyperthermia combined with irradiation to embryos markedly increased and was positively related to hyperthermia intensity and duration; hyperthermia with irradiation had compound action on reducement of embryonic brain proteins in early embryo (P< 0.01) and induced the synthesis of brain HSP70. Conclusion There was certain relativity of nervous development induced by hyperthermia combined with irradiation and synthesis of embryonic brain proteins or induction of HSP70.
胚胎、组织器官和细胞对各种异常生理环境做出应答反应的主要产物之一是热休克蛋白基因编码的热应激蛋白(heat shock protein,HSPs)合成增多,HSPs和脑蛋白质含量变化能准确反映脑分化和脑损伤程度，文献报道多为单一的高热或电离辐射可能对胚胎和神经系统发育产生效应。本研究试图探讨高温与辐射联合对胚胎神经系统畸形的影响，为人类的优生优育提供科学依据。
1.1 实验对象 选取由河南省实验动物中心繁育提供的健康未生育的SD雌性大鼠(体重190～210g)和雄性大鼠(225～275g)为实验对象。
1.3 分组与处理 将130只孕鼠按随机抽签分成13组，每组10只。于妊娠第8，9d分别接受60Co及γ-射线全身照射各1次，剂量1.0Gy；第10d每组各置温箱中,分别使其肛温保持37±0.5℃，41±0.5℃，42±0.5℃,并持续3，4，5min。孕鼠移出温箱2h后，每组随机取5只，脱颈法处死，取出胎鼠，取全脑组织制备匀浆［1］，测量HSP70和蛋白质；18d后每组随机取5只，脱颈法处死，消毒后剖腹，解剖镜下依次剥离蜕膜、Reicherts膜、卵黄膜和羊膜，然后将分离的胚胎置于光镜下观察胚胎神经系统畸形状况。
1.4.1脑蛋白质检测 取匀浆上清液5μL按Lowry氏法［2］测定总蛋白含量。