Effect of methotrexate and leucovorin on female reproductive tract of albino rats

Abstract

Methotrexate (MTX) an antifolate drug and leucovorin its antidote, are used in the treatment of both neoplastic and non-neoplastic diseases in young women. We hypothesize that MTX treatment might comprise a deleterious effect on fast proliferating reproductive cells, an unavoidable and unwanted side effect. MTX given dose dependently to rats for 20 days prevented vaginal cyclicity and caused a reduction in serum progesterone and estradiol. External morphology of reproductive tract displayed thinning of organs and reduction in their weights. To reveal mechanism of MTX action, we examined the histology of ovary, oviduct, uterus, cervix and vagina. Results suggested that in a dose-dependent fashion MTX restrained preantral and antral follicular growth in ovary. Epithelium and stroma of oviduct, uterus, cervix and vagina were disrupted and lost their normal structures. Such alterations in ovarian function raised serum follicle stimulating hormone, luteinizing hormonal profiles. Expression of steroidogenic acute regulatory protein and P450 cholesterol side chain cleavage gene, which are both essential for steroidogenesis, markedly decreased in ovary upon MTX treatment. Total RNA, DNA and protein concentrations, glucose 6 phosphate dehydrogenase, lactate dehydrogenase and alkaline phosphatase enzyme activities in ovary were distinctly altered. Leucovorin supplementation and withdrawal of the treatment, improved MTX caused effects partially. These results for the first time indicate that the malfunction of female reproductive organs by MTX treatment in young women is not only correlated to the disrupted circulating levels of hormones and histoarchitecture of tissues but also discrepancies in steroidogenic genes and hormone regulated enzyme activities in ovary.

Anti-Implantation Activity of Methtrexate and Leucovorin in Albino Rats

“…Reduction in maternal body weights may also be due to the suppressed placental secretions of progesterone and umbilical biomarkers, which may mediate maternal body mass on fetal development (45). Previous studies from our group revealed that MTX attenuates progesterone, estrogen, FSH and LH levels in regular cycling rats (29). Because carbohydrate is the primary metabolic energy substrate, an increase in body glycogen stores at birth may improve the chance of survival for the newborn.…”

“…It is well established that corpora lutea become dependent upon LH for maintenance of progesterone secretion during mid pregnancy (48). In our previous studies we established that progesterone and LH surges alter in MTX treated animals and that the drug has an antiprogestational activity (29,32). Given that the gonads regulate their own trophic support with positive and negative controls over the secretion of the pituitary gonadotropins FSH and LH, a decrease in number of CL observed in MTX treated animals in the current study can be correlated to the inhibition of steroid levels.…”

“…LCN was injected after 4hrs of MTXHD treatment (29). High dose MTX treated rats with respective control group were separated and the treatment was withdrawn.…”

“…Two different doses of MTX, 0.015 mg and 0.05 mg/kg body weight, were chosen as described earlier (29) to study the effects on rat pregnancy. The use of massive doses of MTX, followed after an interval by leucovorin, a folinic acid, allowed the effects of transient, complete inhibition of DNA synthesis to be studied (29,34,35). The present report concerns the effects on the rat embryo and fetus of varying doses of exposure to methotrexate followed by leucovorin, a folinic acid.…”

“…Because the affinity of dihydrofolate reductase (DHFR) for MTX is far greater than its affinity for folic acid, complete reversal of anti-folate effects of MTX requires administration of folinic acid and is known that when given soon after MTX exposure, LCN virtually eliminates teratogenecity effects (28). Our previous studies show evidence that MTX treatment disrupts histoarchitecture of ovary, oviduct, uterus, cervix and vagina, attenuates gonadotropin, steroid hormone levels, genes involved in carbohydrate metabolism (29,30,31) and antiestrogenic and antiprogestational properties of MTX (32). The very early embryo is made up of only a few cells, which are not yet specialized, damage to a critical number of progenitor cells at this stage will result in failure to implant, miscarriage and death of the embryo (33).…”