人参皂甙对中枢儿茶酚胺昼夜节律影响的余弦法分析

INFLUENCE OF GINSENG SAPONIN ON THE CIRCADIAN RHYTHM IN BRAIN CATECHOLAMINE

用荧光分光计法测定小鼠脑内去甲肾上腺素(NE)和多巴胺(DA)含量的正常昼夜节律变化以及人参总皂甙和利血平等药物对中枢儿茶酚胺昼夜节律的影响。小鼠脑内NE和DA呈现明显的生理节律,峰值期均在暗期出现,而光期含量均较低。人参皂甙(GS)对中枢儿茶酚胺的作用强弱或有无依给药昼夜时辰而异。在暗期ip GS使NE明显降低,而在光期投药则否。对于DA,只有12:00时投药有升高作用,而在其余时间投药则无明显影响。为验证上述结果,ip利血平耗竭脑内单胺类递质,则NE和DA的水平在昼夜不同时辰均展示明显降低,但仍然呈现出有意义的昼夜节律变化。此外,乙醇对中枢儿茶酚胺亦有降低作用。

The circadian levels of norepinephrine ( NE ) and dopamiae (DA) in the whole brain were determined spectrofluorometrically in control mice and in mice pretreated with ginseng saponin. All animals were adapted for a minimum period of 2 weeks to an environmental room equipped with, an automatically timed 12h-light and 12h-dark illumination cycle before experiment. Data obtained at 4 h intervals for 48h spans were analyzed by the mean cosinor method. It has been proved that the catecholamine concentrations in the brain vary diurnally. The whole brain NE and DA contents were highest during the middle of dark phase and decreased to a low levels after the onset of light phase. In administration of ginseng saponin altered the circadian pattern and ( or ) levels of brain catecholamine over controls. In order to check the above results reserpine was injected to mice. The levels of NE and DA remarkedly depleted at the times studied, and they showed a significant circadian rhythms as well. It seems that ginseng saponin selectively modulates the circadian variations of brain NE and DA, and its effects may be as a cosinor function of the time of day.