Experimental study on the embryotoxic effects of hyperthermia and their prevention

在胚胎前和后出生发育的影响中，胎儿超热在微观中被调查。超热症被认为是在ICR第8天的恶作剧中被淹没在热水中。在水坝上暴露42 ° C为12.5-15分钟，到43 ° C为7.5-10分钟，外部畸形的动物明显增加，并以与剂量有关的标志。外部神经管的损坏是最常见的。胚胎和胎儿死亡和骨骼变形也增加了跟随热压力的情况。在热暴露后的间隔，胚胎电话部分为光显微镜准备。在3-12小时后，一些损伤的细胞在神经表皮组织中被抑制，在3-12小时后被抑制，在小鼠胚胎中，神经管变形会导致物质超热的结果可能来自细胞生长和胚胎神经表皮的部分退化。怀孕的ICR ... More 老鼠在42 ° C或43 ° C的温度下，每天10分钟一次或两次，经过12天15次的手势和其后代的自然发展被观察到。在11周的年龄中，产后体重的增加和他们的大脑体重比控制动物的价值要小。与控制相比较，完全加热的老鼠在一个开阔的田野里活动，在一个装满水的多个T形迷宫里学习得很慢，在一个垃圾箱里。因此，老鼠中的先天性高体温表明，在后自然期期间，身体和大脑的生长受到抑制，并对他们的情感和学习能力产生不利影响。怀孕的ICR老鼠被注射成单剂量25%的乙醇和/或在42 ° C的高温压力，每天8次招待会。用乙醇（0.01-0.02毫升/克）和加热（10分钟）联合治疗，当他们给予或给予1小时分开时，结果在溶液和外部正规肥料的显著增加。骨骼形态学和视觉变异也增加了显著的后续活动，对两种代理商进行了大量的曝光。这些结果表明，当每一种物质都受到干扰时，乙醇和热在老鼠中具有协同的超原性阈值。Less（低）

The effects of maternal hyperthermia during pregnancy on pre- and postnatal development of the offspring was investigated in mice.1. Hyperthermia was induced in ICR mice on day 8 of gestation by immersing them in hot water. In dams exposed to 42゜C for 12.5-15 min and to 43゜C for 7.5-10 min, externally malformed fetuses increased significantly and in a dose-related manner. Anterior neural tube defects were induced most frequently. Embryonic and fetal death and skeletal malformations also increased following heat-stress.At intervals after heat exposure, sections of embryonic telencephalon were prepared for light microscopy. Mitotic activity was inhibited for at least 3 hr. Some damaged cells became pyknotic and abnormal cells were encountered in the neuroepithelial tissue after 3-12 hr. Thus, neural tube defects in mouse embryos following maternal hyperthermia may result from a temporary cessation of cell proliferation and partial necrosis of the embryonic neuroepithelium.2. Pregnant ICR … More mice were heat-stressed at 42゜C or 43゜C for 10 min once or twice daily on days 12 through 15 of gestation and the postnatal development of their offspring was observed. Postnatal weight gain of the offspring and their brain weight at 11 weeks of age were smaller than the values for control animals. As compared with controls, prenatally heated mice were hypoactive in an open field and learned slowly in a waterfilled multiple T-maze and in a shuttle box. Thus, prenatal brief hyperthermia in mice was shown to suppress the body and brain growth during the postnatal period and adversely affect their emotionality and learning capacity.3. Pregnant ICR mice were injected with a single dose of 25% ethanol and/or heat-stressed at 42゜C on day 8 of gestation. Combined treatment with ethanol(0.01-0.02 ml/g) and heat (10 min), when they were given concurrently or 1 hr apart, resulted in a significant increase of resorptions and externally malformedfetuses. Skeletal malformations and visceral variations also increased significantly following a cuncurrent exposure to both agents. These results indicate that ethanol and heat can be synergistically teratogenic in mice when the doses of each agent are below the teratogenic threshold. Less