褪黑素对大鼠妊娠结局的影响(英文)

Effect of melatonin supplementation on pregnancy outcome in Wistar-Kyoto and Sprague-Dawley rats

褪黑素能调节多项生理功能，但其对妊娠结局的影响所知甚少。本研究旨在探讨补充褪黑素对12～1aN龄的Wistar-Kyoto（WKY）和Sprague-Dawley（SD）大鼠妊娠结局的影响。动情前期确认后，每只雌性大鼠与一只同品种雄性大鼠同笼饲养过夜，第二天阴道涂片确认交配后，雌性大鼠转移至单独的代谢笼，WKY大鼠每天给予含0、25、50或100mg／kg褪黑素的饮水，SD大鼠则每天给予含0或100mg／kg褪黑素的饮水，从怀孕第一天持续至产后21天。记录母鼠体重、孕期、窝产仔数、仔鼠出生体重和出生后7～42d体重及仔鼠死亡率，使用重复测量的方差分析对数据进行分析。结果显示，与对照组相比，褪黑素组母鼠孕期体重增长较小（P〈0．01），窝产仔数减少（尸〈0．01），仔鼠平均出生体重仅在100mg／kg褪黑素组显著降低（P〈0．001），出生后7～42d仔鼠平均体重显著降低（P〈0．01）。25和100mg／kg褪黑素组WKY仔鼠死亡率分别为9．5％和21．6％，且都发生在断奶21天后。以上结果提示，产前和产后补充褪黑素会严重影响WKY和SD大鼠窝产仔数、仔鼠生长和死亡率。

Although melatonin supplementation is known to influence numerous physiological functions, little is however known of its effects on pregnancy outcome. This study investigated the effects of melatonin supplementation on pregnancy outcome in Wistar- Kyoto （WKY） and Sprague-Dawley （SD） rats aged 12-13 weeks. Upon confirmation of proestrus, each female rat was housed over- night with a male of the same strain. On the next morning, following confirmation of mating （vaginal smear）, WKY female rats were isolated into individual metabolic cages and given 0, 25, 50 or 100 mg/kg per day of melatonin in drinking water from day 1 of preg- nancy to day 21 postpartum. SD females were given 0 or 100 mg/kg per day of melatonin. Maternal weight, duration of pregnancy, litter size, birth weight and body weight of pups up to day 42, and pup mortality were recorded. Data were analyzed using ANOVA for repeated measures. Compared to controls, maternal weight gain during pregnancy was significantly lower in melatonin-supplemented dams （P 〈 0.01）. Litter size was significantly smaller in melatonin-supplemented dams （P 〈 0.01）. Mean birth weight of pups was sig- nificantly lower only in pups of dams given 100 mg/kg per day of melatonin （P 〈 0.001）. Mean body weight of pups of dams given melatonin was significantly lower than controls （P 〈 0.01）. Pup mortalities were 9.5% and 21.6% in WKY dams given 25 and 100 mg/ kg per day of melatonin respectively, and all pup deaths occurred after day 21 of weaning. The results suggest that melatonin supple- mentation during antenatal and postpartum period appears to adversely affect litter size, pup growth and mortality in WKY and SD rats. The precise mechanism causing the death is not clear.