Effect Of Subacute Selenium Poisoning On Reproductive Endocrine In Female Mice

To study the effects of the subacute selenium poisoning on the reproductive endocrinology in the female mice, forty female mice (7weeks old) weighed20±2g as the study object were randomly divided into four groups with10of each group after a week of adaptive feeding. Intragastric administration of sodium selenite was conducted for30days according to the low dose group0.14mg/kg·d-1(1/80LD50), the middle dose group0.54mg/kg·d-1(1/20LD50), the high dose group2.16mg/kg·d-1(1/5LD50) and the control group the same volume of saline. Every morning at9:00, estrous cycle were measured by smear method of vagina. The body weight was measured to judge the growth condition every10days. The uterus, the ovary and the hypophysis were fixed by formalin and cryopreservation after measuring at the thirtieth day. The visceral index of the mice was calculationed. The histologicalstructure of the ovary and the hypophysis were observed by the optical microscope and the electron microscope. The energy metabolism and the oxidation resistance of the ovary and the hypophysis were measured by ELISA kits. The content of the selenium in the ovary and the hypophysis was measured by the atomic fluorescence spectrophotometer. Estrogen (E2), progesterone (P4), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and cholesterol (T-CHO) in serum were measured at the end of experiment by radio immunoassay.The results showed that the LD50of the selenium in the female mice was10.8mg/kg. With the increasing of selenium dosage and the duration, the poisoning symptoms appeared such as messy coat, losing appetite, losing weight, losing hair and dispiritedness and so on. The ovary and the uterus in the control group developed well, but the experimental groups showed that both ovary and uterus’s cell degeneration and necrosis with the typical feature of apoptosis. The cumulative toxicity index was12which was showed the weak accumulation. Excessive amounts of selenium could inhibit the growth and development of the mice. It could damage the organization structure of the ovary and the uterus, which could cause reproductive dysfunction. Subacute selenium poisoning could influence the estrous cycle of the female mice and the secretion of E2, P4, LH, FSH and T-CHO. It could also reduce the activity of SDH and LDH in the ovary and the uterus to reduce energy supply, which to suppress germ cell’s function and disrupt the reproductive endocrine of the female mice.Selenium can made the MDA of the ovary and the uterus increased significantly and SOD drop significantly,which means that high dose of the selenium can made the cell be in the situation of oxidative stress and the function of the cell was weaken. With the high dose of the selenium.the energy of the GSH-PX is negatively related to the trend,which means the selenium has the dual-direction regulation.With the increase of the selenium,the dose of the selenium in the ovary and the uterus increase too,which shows dose-effect relationship.This experiment systematically studied the effect of subacute selenium poisoning on the reproductive endocrinology of the female mice on the level of organ, cellular, subcellular, confirmed the double-way adjusting effect of sodium selenite on reproductive endocrinology of the female mice, enriched the knowledge in toxicology and provided a scientific basis for clinical supplement of selenium.