Zhong D Z, Pei C, Xiu-Qin L
Department of Toxicology, Beijing Medical University, People's Republic of China.
Neurotoxicol Teratol. 1996 Nov-Dec;18(6):703-9. doi: 10.1016/s0892-0362(96)00127-4.
Thirty-two pregnant adult LACA mice were randomly assigned to one of five exposure groups: control, 38 degrees C, 42 degrees C, irradiation, and 42 degrees C + irradiation. Animals were exposed on gestation day 9 to either 38 degrees C waterbath for 5 min, 42 degrees C waterbath for 5 min, treatment with 0.5 Gy of 60Co gamma irradiation, or pretreatment at 42 degrees C waterbath for 5 min following by 0.5 Gy of 60CO gamma irradiation. On postnatal day 7, litters were reduced to a maximum of eight pups per litter, with equal members of male and female offspring whenever possible. A total of 216 pups were observed for the age of acquisition of four physiological landmarks (pinna detachment, incisor eruption, eye opening, testes descent), six developmental reflexes (surface righting, cliff avoidance, auditory startle, air righting, visual placing, hindlimb splaying), and examination of learning and memory function. These studies, at threshold exposure levels to hyperthermia and ionizing radiation, indicate there is no consistent significant additional postnatal effect when pregnant mice are exposed to both of these agents. These studies are important for our understanding of the relative long-range effects of prenatal exposure to hyperthermia and acute dose irradiation early in gestation on neurobehavioral teratogenesis.
32只成年怀孕LACA小鼠被随机分配到五个暴露组之一：对照组、38摄氏度组、42摄氏度组、辐射组和42摄氏度+辐射组。在妊娠第9天，将动物暴露于38摄氏度水浴中5分钟、42摄氏度水浴中5分钟、用0.5 Gy的60Coγ射线照射，或先在42摄氏度水浴中预处理5分钟，然后再用0.5 Gy的60Coγ射线照射。在出生后第7天，每窝幼崽最多减少到8只，尽可能使雄性和雌性后代数量相等。总共观察了216只幼崽，以了解四个生理标志（耳廓分离、门齿萌出、睁眼、睾丸下降）的获得年龄、六种发育反射（表面翻正、悬崖回避、听觉惊跳、空中翻正、视觉定位、后肢伸展），并检查学习和记忆功能。这些在热应激和电离辐射阈值暴露水平下进行的研究表明，当怀孕小鼠同时暴露于这两种因素时，没有一致的显著产后附加效应。这些研究对于我们理解孕期早期产前暴露于热应激和急性剂量辐射对神经行为致畸的相对长期影响具有重要意义。
