大鼠运动病敏感性性别差异与精氨酸加压素神经内分泌水平的关系

目的:探讨AVP与运动病性别差异间的联系,为认识运动病的发病机制提供实验依据。方法:采用大鼠条件性厌食症(CTA)模型。SD大鼠86只,雌雄各半,用放射免疫分析法和Western-Blot法比较旋转前后血浆及垂体中AVP和V1b受体表达的差异。结果:旋转刺激后各大鼠糖精水饮用量均较旋转前明显减少,而雌性大鼠糖精水饮用量的减少程度高于雄性大鼠。雌性大鼠血浆AVP含量在基础状态下高于雄性,旋转刺激后即开始下降,8h差异显著,24h后基本恢复正常;雄性大鼠旋转前后血浆AVP水平变化不显著。雌性大鼠垂体AVP含量在基础状态下也高于雄性大鼠,旋转刺激后8h雌性大鼠垂体AVP含量下降,旋转后24h垂体AVP含量较旋转前有明显降低;雄性大鼠旋转后8h垂体AVP含量较旋转前明显下降,但降幅不及雌性大鼠,旋转后24h已近恢复。与应激反应密切相关的垂体其V1b受体表达水平,在基础状态下,雌性大鼠显著高于雄性;接受旋转刺激后,雌性大鼠表达水平均明显降低,而雄性大鼠则无显著性改变。结论:运动病诱发刺激后,雌雄性大鼠血浆及垂体中AVP及其V1b受体的表达均有差异,提示AVP在运动病敏感性性别差异中可能起着重要作用。

Role of AVP and V1 b receptors in the sexual differences of susceptibility to motion sickness in rats

Objective:To investigate the relationship between sexual differences of MS and AVP levels of plasma and pituitary and the expression of V1b receptors , and to supply experimental evidence for further understanding of the mechanisms of MS. Methods:The Conditioned Taste Aversion (CTA) model of MS was adopted. 86 rats were used in the experiment, 43 being male and 43 being female. 50 were used for detecting the level of AVP in plasma and pituitary with radioimmunoassay(RIA).The rest (36) were used to evaluate whether the expression of V1b receptor in the pituitary gland was different between male and female rats exposed to rotatory stimulation by Western Blot. Results:The drinking volume of rats obviously decreased with rotation, and the extent of decrease for female rats was higher than that of male rats significantly. The plasma AVP concentration of female rats was significantly higher than that of males under normal conditions.It reduced significantly 8h after rotation, and recovered close to control level 24 hours after rotation. However, no significant change was found in male rats after rotation.In additional to the plasma AVP, the change of AVP concentration in the pituitary was also detected.The pituitary AVP level of the female rats was significantly higher than that of the male rats under normal conditions,and the level decreased 8h after rotation,and there was a significant decrease 24h after rotation. Similarly, the pituitary AVP level of male rats also decreased significantly at 8h after rotation,but this decrease was not comparable to that of the females. 24h after rotation the pituitary AVP level almost recovered in male rats. In the pituitary gland, which was greatly related to the stress response,the expression level of V1b receptor in female rats were signifcantly higher than that of the male rats, but they decreased significantly after rotation, while no apparent change was detected in the male rats. Conclusion:The changes of plasma and pituitary AVP and V1b receptor levels after rotation are significantly different between male and female rats. Our results indicate that AVP may play an important role in the mechanism of sexual differnce in susceptibility of MS.