The Effects Of Formaldehyde On Reproductive Cell Of Female Mice

[Objective] To study the effects of formaldehyde on ovarian endocrine and genetic material in oocyte and search estimation index, We observed the general toxiciry, estrous cycle, ovarian histopathological structure and ultrastructure of oocyte; investigated the E2 and LH level in blood serum and chromosomal aberration in oocyte of female Kunming mice who were exposed to formaldehyde by ip. To discover the toxicity mechanism of formaldehyde on oocyte, we detected the GSH level in the ovarian tissue.[Methods] Female Kunming mice were used. Formaldehyde groups had been exposed to formaldehyde by ip for 5 days. Formaldehyde doses were: 1.25mg/kg-bw, 2.50 mg/kg-bw, 5.00 mg/kg-bw. We killed some mice at the day 6th , the others were continue to expose to formaldehyde and observe their estrous cycle. HE staining was used to study the pathological changes happened in ovarian tissue. Uranium acetate and lead acetate double staining was used to study the ultrastructure of oocyte. E2 and LH level in blood serum was measured by radioimrnunoassay reagent kit. To study the injury of genetic materials in oocyte, we collected oocyte by ovarian stimulation, and observed chromosome aberration ratio in the oocyte.[Result] 1. The estrous was shorten, estrous cycle prolongation and irregular in toxicant exposure groups; 2. A few mature follicles of high and medial dose groups' have low-grade degeneration. At the same time interstitial blood vessel congested, luteal cell vacuolar degeneration; 3. The mitochondria of oocytes and cumulus cells in high and medial dose groups swelling and vacuolar degeneration, but rough surfaced endoplasmic reticulum (RER) were normal and abundance. There are some oocytes disintegration liquefaction, only leave some cell debris; 4.-3-ABSTRACTThere was significant decrease of GSH and E* level in high dose group (p<0.01), and decrease current of LH level; 5. The chromosome aberration ratio in the oocyte was increased in all formaldehyde groups. There were a dose?effect relationship between formaldehyde groups and the control group (p<0.01). And formaldehyde has aneuploid mutagenesis.[Conclusion] 1. Formaldehyde could damage ovarian histopathological structure and ultrastructure of oocytereproduction; 2. Formaldehyde could decrease reproductive endocrine and made estrous cycle disorder; 3. Formaldehyde could damage genetic materials in oocyte; 4. Formaldehyde could cause lipid peroxidation in ovarian tissue. The effect of lipid peroxidation may be one of the toxicity mechanisms of formaldehyde on genetic materials; 5. Observing estrous cycle is the estimation index that can be used to judge the damage on reproduction endocrine of formaldehyde .