大鼠下丘脑SST及垂体SSTR-1对6周递增负荷运动的应答和适应

Responsive and Adaptive Changes of Hypothalamus SST and Pituitary SSTR-1 of Rat Brought by Incremental Exercise for 6 Weeks

目的观察递增负荷运动造成免疫功能下降过程中生长抑素(SST)和生长抑素1型受体(SSTR-1)的应答和适应变化特征,探讨其可能机理。方法 120只SD雄性大鼠随机分为试验组和对照组,又依据取样时间的不同分为15小组,建立递增负荷训练模型。分别于第0、2、4、6周末的运动前安静状态、运动后即刻和运动后3 h,将大鼠全身灌流固定后取脑及垂体,冠状位连续石蜡切片后免疫组织化学染色,所得图像使用Image-Pro Plus6.0图像分析软件分析。结果 (1)下丘脑中SST主要分布在3V旁室周核的上半部分,为胞质阳性;SSTR-1主要分布在垂体边缘,为胞膜阳性。(2)各组大鼠下丘脑SST及垂体SSTR-1对6周递增负荷运动的适应性变化特征为:①对照组大鼠SST在6周内无显著性差异,SSTR-1在第2周时最低,依次为第0、4周,至第6周时最高;②2周安静状态SST较0周明显增多,4周安静时下降至略低于0周,第6周则下降更低;SSTR-1安静状态下4周最高,依次为第6、2和0周。(3)各周大鼠下丘脑SST及垂体SSTR-1对1次性运动的应答性变化特征为:①第0、4周运动后即刻SST的表达增多,而第2、6周减少;训练第0、2、4周大鼠运动后3 h均可恢复至运动前安静状态,第6周则不能恢复;②SSTR-1在运动即刻及恢复3 h后的变化规律与SST一致,但运动结束后3 h的恢复程度较SST低,有滞后现象。结论 (1)在长期递增负荷运动影响下,安静状态时大鼠下丘脑SST运动初期一过性增加,之后呈下降趋势,适宜运动可以减少安静状态SST的表达,有利于维持自身的免疫机能;(2)大鼠垂体SSTR-1对1次性运动应答性反应的规律与SST一致,即接受适宜运动训练的个体运动后即刻表达增多,处于运动应激动员和衰竭阶段的个体运动后即刻表达减少;(3)运动后即刻及安静状态下,过度训练均引起大鼠下丘脑SST及垂体SSTR-1表达减少,对于对抗免疫抑制的发展具有重要意义,是机体防御抑制保护的表现。

Objective Through observing the responsive and adaptive characteristics of hypothalamus SST and pituitary SSTR - 1 to incremental exercise of 6 weeks in rat, this research is try to explores the possible mechanism. Methods 120 SD rats were randomly divided into 2 groups, namely the experimental group and the control group. According to different time of sampling, the 2 groups were further divided into 15 groups again. Then, the 6 weeks of incremental trained model was established. The sample of rat＇ s brain and pituitary were dawn out after perfusion fixation in the wake of respectively 0, 2, 4 and 6 weeks under the condition of quiet situation before exercise, immediate after exercise and 3 hours after exercise respectively. And the samples were stained with immunohistochemical after consecutive coronal paraffin section. The images were analyzed and processed by Image - Pro Plus 6.0 software. Results （ 1 ） SST was mainly distributed in the top half of periventricular nucleus cytoplasm next to 3V in the hypothalamus, and intracellular fluid showed positive; while SSTR - 1 were mainly found in pituitary edge membrane whose cell membrane showed positive. （2）The adaptive changing characteristics of SST in hypothalamus and SSTR - 1 in pituitary in each group rats to incremental exercise of 6 - week with incremental load were as follows ： ①SST of rats in the controlled group has no significant difference during 6 weeks, SSTR - 1 was least in the 2nd weeks, followed by the before training and the 4th weeks, and was maximum in the sixth weeks; ②for quiet state, SST of 2 weeks increased significantly compared with that of 0 weeks, 4 weeks slightly lower than 0 weeks, and 6 weeks more lower ; SSTR - 1 has maximum level in 4 weeks, followed by 6, 2 and 0 weeks. （3） In each week, the responsive changing characteristics of SST in hypothalamus and SSTR - 1 in pituitary of rats to one single exercise were as follows ： ① the expression of SST increased in 0 and 4 week immediately after the exercise, but reduced in 2 and 6 week reduced ; 3 hours after exercise, the SST could restore to level of quiet status in the exercise of 0,2 and 4 weeks, but not 6 weeks; ②the changing regulation of SSTR - 1 was similar to SST at immediately after the exercise and 3 hours after exercise, but the level of resto- ring of 3 hours after exercise was lower than SST, there is delay phenomenon. Conclutions （ 1 ） The expression of hypothalamus SST showed tendency to ascend during the initial period and followed by descendence caused by long - term incremental exercise. The sports with suitable amont can reduce expression of hypothalamus SST of quiet stated rats, which is helpful to maintain the autoimmune function of body. （2） The changing responsive regulation of rats pituitary SSTR - 1 is consistent with SST induced by disposable exercise. There was increased expression of SSTR - 1 in rat that accepted sports with suitable load, and decreased expression during exercise stress and exhaustive exercise rat in immediately after exercise. （ 3 ） The overtraining method decreases the expression of the hypothalamus SST and pituitary SSTR - 1 of rats on the condition of the rest, before exercise and immediate after exercise. It is significant for us to decrease the immunosuppressive effect, possibly one of the expressions of body self - defense.