甲氨蝶呤对大鼠输卵管雌孕激素受体的影响

目的观察不同剂量甲氨蝶呤（MTX）对假孕SD大鼠输卵管雌孕激素受体的损伤，探讨MTX治疗后对后续妊娠的潜在影响，为临床使用甲氨蝶呤保守治疗异位妊娠提供理性的合理选择。方法40只SD雌性大鼠，致假孕状态后再MTX腹腔注射，随机分为1m/kg组、2mg／kg组、5m/kg组及对照组（腹腔注射生理盐水），10d后处死各组大鼠，取双侧输卵管壶腹部组织，进行雌、孕激素受体的免疫组化染色。结果ER阳性表达率在不同剂量组的差异具均有统计学意义（P〈0．05），表现为随着MTX剂量的增加，ER阳性表达下降。PR在MTX处理各组输卵管黏膜上皮中的表达与对照组差异无统计学意义（P〉0．05）。结论MTX可损伤输卵管雌激素受体，且损伤效应存在一定的量-效关系，提示临床中使用MTX保守治疗异位妊娠时，应减少剂量，否则可能会造成后续的再次异位妊娠或继发不孕。

The effect of methotrexate (MTX) on the fallopian tubes in rats

Objective To investigate the adverse effect of increasing doses of methotrexate （MTX） on the fallopian tubes in rats and explore the dosage in which tubal pregnancy can be treated reasonably with methotrexate. Methods The study was carried out on 40 pseudocyesis SD rats. Increasing doses of MTX were administrated to the rats by intraperitoneal injection： 1 mg/kg in group 1,2 mg/kg in group 2 and 5 mg/kg in group 3. Rats in group 4 only received injections of physiological saline and serve as control group. Ten days after the intraperitoneal injection, the fallopian tubes of the 40 rats were removed respectively and submitted to examination immunohistochemistry staining for the expressions of ER and PR. Results The immunohistochemical expression of estrogen receptor （ER） within endosalpinx significantly decreased in parallel with the increased doses of methotrexate （MTX） （among group 1,2,3：P 〈 0. 05 ） ; ER expression density in all treatment group were less than control group （P 〈 0. 05）. However, the expression of PR within endosalpinx showed no significant difference among all treatment groups （ P 〉 0.05 ）. Conclusions Decreased ER expression does occur within fallopian tubes resulting from administration of MTX at dose of greater than 1 mg/kg. Methotrexate should be used in a safe range of dosage in ectopic pregnancy in order to effectively avoided near or long - term impairment and complications which could contribute to certain degree in the causation of infertility and recurrent ectopic pregnancy.