Tang P A, Fewell J E, Eliason H L
Department of Physiology and Biophysics, Health Sciences Centre, University of Calgary, Calgary, Alberta, Canada T2N 4N1.
J Appl Physiol (1985). 1999 Jul;87(1):170-4. doi: 10.1152/jappl.1999.87.1.170.
Near the term of pregnancy, rats have an attenuated core temperature response on exposure to a novel environment (e.g., a simulated open field) compared with that observed early in pregnancy or in nonpregnant rats. The present experiments were carried out on 26 nonpregnant and 26 pregnant rats to test the hypothesis that arginine vasopressin, functioning as an endogenous antipyretic substance in the central nervous system, mediates this attenuated core temperature response. Exposure to a simulated open field after intracerebroventricular (ICV) vehicle produced a significant increase in core temperature in both nonpregnant and pregnant animals, the magnitude and duration of which were greater in the nonpregnant rats. In nonpregnant rats, exposure to a simulated open field after ICV vasopressin V(1)-receptor antagonist altered the pattern of the core temperature response but not the core temperature index compared with that observed on exposure to a simulated open field after ICV vehicle. In pregnant animals, ICV vasopressin V(1)-receptor antagonist did not alter the core temperature response to a simulated open field compared with that observed after ICV vehicle. Thus our data do not support the hypothesis that a pregnancy-related activation of arginine vasopressin attenuates the core temperature response to a simulated open field in rats near the term of pregnancy.
在接近妊娠末期时，与妊娠早期或未孕大鼠相比，大鼠在暴露于新环境（如模拟旷场）时核心体温反应减弱。本实验对26只未孕大鼠和26只孕鼠进行，以检验精氨酸加压素作为中枢神经系统内源性解热物质介导这种核心体温反应减弱的假说。脑室内注射赋形剂后暴露于模拟旷场，未孕和孕鼠的核心体温均显著升高，未孕大鼠的升高幅度和持续时间更大。在未孕大鼠中，脑室内注射加压素V(1)受体拮抗剂后暴露于模拟旷场，与脑室内注射赋形剂后暴露于模拟旷场相比，核心体温反应模式改变，但核心体温指数未变。在孕鼠中，与脑室内注射赋形剂后相比，脑室内注射加压素V(1)受体拮抗剂未改变对模拟旷场的核心体温反应。因此，我们的数据不支持精氨酸加压素与妊娠相关的激活减弱接近妊娠末期大鼠对模拟旷场的核心体温反应这一假说。
