持续光照对大鼠生殖节律的影响及中药干预作用的研究

Effect of continuous light on reproductive rhythm of rats and intervention effect of Traditional Chinese Medicine

目的光线作为授时因子,调控机体昼夜节律。夜间过度照明导致光污染,会干扰昼夜节律,进而对机体产生不良影响。文章针对过度光照对于女性生殖内分泌的不良影响及寻求有效的治疗方法,开展动物实验。方法筛选出185只动情周期正常的2月龄性成熟雌性SD大鼠,随机抽签法选取60只入对照组,给予正常光照条件。剩余大鼠给予光照强度为(300±20)lux的24h/d持续光照的条件造模,持续50d,以期获得生殖节律紊乱模型。将成模大鼠(100只)随机数字表法分为模型组(n=50)和中药组(n=50),中药组给予滋阴补阳序贯中药治疗。模型组和对照组给予等体积等渗盐水灌胃,观察各组大鼠动情周期的变化。20 d后,分时动态采血,比较各组大鼠雌二醇(E2)、孕酮(P)、黄体生成素(LH)、卵泡刺激素(FSH)及褪黑素水平,评估中药治疗效果,并初步从褪黑素角度阐释作用机制。结果在第1天,模型组和中药组E2水平明显低于对照组(P<0.05),第2天中药组显著高于对照组(P<0.05),第3天中药组和模型组E2显著高于对照组(P<0.05)。对照组孕酮在动情前期和动情期较低,动情后期及间期升高,而中药组和模型组波动比较小。在第3天和第4天,模型组孕酮水平显著低于中药组和对照组(P<0.05)。第1天,模型组LH水平[(249.8±50.2)mIU/m L]及中药组[(83.4±37.3)mIU/mL]均显著低于对照组[(420.0±100.4)mIU/mL](P<0.05)。第1天,模型组及中药组FSH表达均显著低于对照组(P<0.05),在第4天,中药组显著低于对照组和模型组(P<0.05)。各组褪黑素比较显示,对照组褪黑素呈现昼低夜高的近日节律变化,最高值几近最低值的5倍;而模型组和中药组均未见明显近日节律变化。结论持续光照可导致大鼠动情周期严重紊乱,丧失节律,中药具有诱导周期重建的作用。持续光照可导致大鼠内分泌紊乱,E2、FSH、LH峰不能形成,排卵障碍,黄体功能不足,中药具有诱导排卵及黄体支持的作用。持续光照可破坏褪黑素的近日节律,中药具有升高褪黑素的作用,这有可能是中药起效的机制。

Objective Light acts as an important zeitgeber and regulates the body＇s circadian rhythm. Excessive lighting at night leads to light pollution, which interferes with the circadian rhythm and thus adversely affects the body. To observe the adverse effect of con- tinuous light on female reproductive endocrinology and explore effec- tive treatment, the animal experiment was carried out. Methods 185 sexual maturity female SD rats in the age of 2 months with normal estrous cycle were enrolled. 60 rats were selected randomly and enrolled into control group. Normal illumination conditions were given. The remaining rats were given 300＋201ux light intensity for 24h/d last for 50 days to get reproductive rhythm disorder model. The model rats （100） were randomly divided into models group （n = 50） and Traditional Chinese Medicine （TCM） group （n= 50）. Traditional Chinese Medicine group was treated with sequential TCM . At last we get 50 rats enrolled into model group and herbal group respectively. The TCM group rats were given therapy of nourishing yin and tonifying yang sequential TCM, while the two other groups were gavaged the same volume of physiological saline. The estrous cycle was observed in all groups. 20 days later, blood were collected dynamically and E2 （estradiol）, P （progesterone）, LH （Luteinizing Hormone）, FSH （Follicle-Stimulating Hormone）and melatonin were compared to evaluate the therapeutic effect of TCM . Finally, try to explain the mechanism of TCM＇s effect from the perspective of melatonin. Results At the first day, E2 was lower in TCM group and models group than control group （P〈 0.05）. At the second day, E2 was higher in traditional Chinese Medicine group than control group （P〈0.05）. At the third day, E2 was higher in TCM group and models group than that in control group （P〈 0.05）. Progesterone in control group showed low level in pre-estrous and estrous period and elevated in the late stage of estrous. Progesterone showed no ob- vious change during the estrous cycle in TCM group and models group. At the third and fourth day, Progesterone was significantly lower in models group than TCM group and control group. At the first day, LH in models group [ （249.8±50.2）mIU/mL] and TCM group [ （ 83.4±37.3 ） mIU/mL ] were significantly lower than control group [ （ 430.0± 100.4） mIU/mL ] （ P〈 0.05 ）. At the first day, FSH in models group and TCM group were significantly lower than control group （P〈0.05）. At the fourth day, FSH in TCM group was signifi- candy lower than control group and models group （P〈0.05）. Compared the melatonin among three groups, the circadian rhythm was high at night but low in the day in control group. The highest level was nearly 5 times higher than the lowest level. Neither the models group nor the TCM group had obvious recent rhythm changes. Conclusion Continuous light can induce disordered estrous cycle and loss of rhythm. Traditional Chinese Medicine can somehow induce circulation reconstruction. Continuous light can induce disordered endocrine, E2, FSH, LH surge abnormal, ovulation failure, luteal phase defect. TCM can induce ovulation and luteal support. Contin- uous light can destroy melatonin circadian rhythm and TCM can increase melatonin , which could be the mechanism of TCM ＂s effect.