左炔诺孕酮和炔雌醚复合不育剂(EP-1)对雌性东方田鼠生殖的影响

The effect of levonorgestrel-quinestrol on female fertility in Microtus fortis

本文在实验室条件下通过一次性灌胃的方式研究了左炔诺孕酮-炔雌醚复合不育剂(EP-1)对雌性东方田鼠激素、生殖系统、胎仔数、受孕率的影响及药效持续时间,旨在检验其应用于野外东方田鼠不育控制的价值。结果表明,各浓度EP-1灌胃均能显著提高雌性东方田鼠的子宫系数,使子宫形态发生变化,对卵巢组织造成损伤,影响卵泡和黄体的发育,但是对雌二醇含量和子宫长度没有明显影响;60 mg/kg EP-1灌胃能显著提高促卵泡刺激素含量和卵巢系数,而10 mg/kg、30 mg/kg EP-1灌胃对二者没有明显影响。室内繁殖实验表明,各浓度EP-1灌胃均能不同程度延迟初次怀孕时间,并降低试鼠的怀孕率和胎仔数,但抗生育作用具有可逆性且与药物浓度相关,10 mg/kg、30 mg/kg和60 mg/kg剂量组生殖系统恢复时间分别为16 d、38 d和52 d。

Our laboratory study evaluated the effects of a contraceptive compound EP- 1（ levonorgestrel- quinestrol） on fertility in female Microtus fortis calamorum,as measured by changes in hormone levels,reproductive organs,litter size,pregnancy rate and reproduction interval. Some dosages of EP- 1 significantly affected uterus coefficient,follicle- stimulating hormone（ FSH） levels,ovary coefficient and ovarian tissue morphology,but didn＇t obviously affect uterus length or estradiol levels. A dose of 60 mg / kg EP- 1 significantly increased FSH levels and ovary coefficients,however doses of10 mg / kg or 30 mg / kg EP- 1 had no obvious effect on either measurement. Litter size and pregnancy rate were significantly reduced at different dosages of EP- 1. The effective sterilization periods following dosage with 10 mg / kg,30 mg / kg or60 mg / kg of EP- 1 were approximately 16,38 and 52 days respectively. The time taken for measurements to return to pre- dosing conditions was related to the dose of EP- 1. Our results indicate further potential of EP- 1 in reducing fertility for the control of Microtus fortis populations in field conditions.