免疫抑制剂FK506对雌性大鼠性腺轴的影响

Effect of Immunosuppressive Agent FK506 on Hypothalamic-Pituitary-Ovarian Axis in Rats

目的:探讨免疫抑制剂FK506对雌性大鼠生殖内分泌功能的影响。方法:将Wistar大鼠随机分为4组:对照组、低剂量组、中剂量组和高剂量组,分别每日给予生理盐水以及不同剂量FK506灌胃(0.2mg/kg、1mg/kg、2mg/kg)×42d。用药前2周及用药期间每日行阴道涂片检查,观察大鼠动情周期变化;停药后于动情间期处死大鼠,放免法检测血清E2、P、LH水平,免疫组化法检测卵巢、垂体、下丘脑雌激素受体(ER)表达水平。结果:①连续给药42d后,中、高剂量组大鼠动情周期平均天数(5.0d、5.5d)均较对照组(4.1d)显著延长(P<0.05,P<0.01)。②中、高剂量组大鼠平均血清孕酮(P)水平(42.5ng/ml、32.8ng/ml)与对照组(78.9ng/m)相比较明显降低(P均<0.01)。低、中、高剂量组大鼠平均血清雌二醇(E2)水平(9.4pg/ml,7.7pg/ml,8.3pg/ml)也明显低于对照组(14.3pg/ml)(P均<0.05)。各组间黄体生成素(LH)水平无显著差异。③大鼠卵巢、垂体以及下丘脑组织中雌激素受体表达与FK506剂量呈负相关。结论:大鼠用药后血清P及E2水平明显下降,性腺轴各组织器官ER表达也发生不同程度下调,上述作用呈一定的量-效关系。提示FK506长期用药对大鼠生殖内分泌功能可造成一定程度的影响。

Objective： To investigate the impact of immunosuppressive agent FK506 on reproductive endocrine in female rats. Methods： Female Wistar rats were randomly divided into following four groups： control group, low-dose group, mid-dose group and high-dose group, and received once daily normal sodium or FK506 （dissolved in NS） by gavage at 0.2 mg/kg, 1.0 mg/kg and 2.0 mg/kg, respectively. Vaginal smear was daily exam ined to determine the estrous cycle from two weeks prior to gavage to the end of experiment. After 42 d of gavage, all experiment animals were sacrificed at anestrus. The serum levels of E2, P and LH were detected by radioimmuoassay （RIA）, and the expression of estrogen receptor （ER） in ovary and brain tissue were detected by immunohistochemistry. Results： （1） After 42 d of gavage, it took longer both in mid-dose and high-dose group （5.0 d and 5.5 d, respectively） than the estrous cycle of rats in control group（4.2 d, P〈0.05, P〈0.01）. （2） The serum levels of P in mid-dose group and in high-dose group （42.5 ng/ml and 32.8 ng/ml, respectively） were lower than that of control group（78.9 ng/ml, both P〈0.01）. The serum levels of E2 in low-dose group, mid-dose group and high-dose group （9.4 pg/ml, 7.7 pg/ml and 8.3 pg/ml, respectively） were all significantly decreased when compared with that in control group （14.3 pg/ml; each P〈0.05）. But the serum levels of LH were not obviously changed among those groups. （3） The expressions of ER in hypothalamus, pituitary and ovarian tissue had a negative correlation with the dose of FK506 in each group. Conclusion： After chronic FK506 employment, the serum levels of E2 and P were decreased, and the expressions of ER in hypothalamus, pituitary and ovarian were down regulated. All the changes indicated that FK506 has impact on the reproductive endocrine function in rats.