下丘脑IL-6对大鼠心功能的调节作用

Effect of hypothalamic IL-6on cardiac function in rats

通过下丘脑促垂体区微量注射白细胞介素-6,记录左心室内压峰值(LVSP)、心率(HR)、瞬时上升速率峰值(dp/dtmax)和瞬时下降速率峰值(-dp/dtmax),探讨SD大鼠下丘脑IL-6对心功能活动的影响及其中枢机制.结果显示:与对照组相比,大鼠下丘脑微量注射IL-6能引起LVSP、HR、dp/dtmax、-dp/dtmax极显著升高(P<0.01),并具有时间效应.注射一氧化氮合酶抑制剂L-硝基精氨酸甲酯后对心功能无明显影响;预先注射L-NAME后再注射IL-6,与单独注射IL-6组无明显差异.与对照组相比,注射阿片肽受体拮抗剂纳洛酮引起LVSP显著下降(P<0.01),其他指标无明显变化.预先注射纳洛酮后能明显抑制IL-6所引起的LVSP、HR、dp/dtmax和-dp/dtmax升高效应(P<0.05,P<0.01).结果表明:下丘脑注射IL-6引起心功能增强效应与一氧化氮通路无关,而是经内源性阿片肽通路介导.

To investigate the effect of hypothalamic interleukin-6 （IL-6） on cardiac function and its central mechanism, IL-6 was microinjected into the hypohysiotrophic area of rats, and the left ventricular systolic pressure peak （LVSP）, heart rate （HR） and the maximum velocity of ascending or descending in intraventricular pressure （± dp/dtmax） were recorded. The results showed that hypothalamic IL-6 induces a significant increase in LVSP, HR, dp/dtmax and -dp/ dtmax with a time-dependent way. Pretreatment with an inhibitor of nitric oxide synthase （L- NAME） had no significant effect on cardiac function and no obvious difference compared with the only injections IL-6. On the contrary, injection of opioid peptides receptor antagonist （naloxone, Nal） results in significant decrease of LVSP （P〈0.01）, and pretreatment with Nal causes the positive effects induced by IL-6. These findings suggest that extrinsic IL-6 microinjected in the hypothalamus plays an important role in enhancing cardiac function via opioid peptides receptor pathway rather than in nitric oxide （NO） pathway.