The Effect Of Cypermethrin And Methylparathion On Endocrine Hormone And Immunological Function

Objective: To study the change of relative viscera weight, reproductive hormone, thyroid hormone and immunological function in rats exposure to combined pesticides of cypermethrin and methylparathion.Method: 2-month old Wistar rats had been divided randomly into 4 groups. Three exposure groups were force-fed one time every two days for 30 days using 1/600 LD50, 1/135 LD50, 1/30 LD50 cypermethrion plus same equivalent doses of methylparathion, respectively. One control group were force-fed vehicle solvent only. Pesticides had been dissolved in vegetable seeds oil. The rats were killed 2 days after one month treatment and the viscera relative weight were measured. The serum genital hormone Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), Estradiol (E2) and Testosterone(T); the serum thyroid hormone Triiodothyronine (T3), Tetraiodothyronine (T4) and Thyroid stimulating hormone (TSH); IgG and IgA level were measured using Radioimmunoassay(RIA). The middle blood were used to measure lymphocyte translation rates and ambivert grainy cell phagocytosis rates, phagocytosis index and compositive index.Results: The relative weight of hypothyroid gland of exposure female groups were heavier than that of the control group (P<0.05), and the relative weight of adrenal gland in exposure male rats were heavier than the control group (P<0.01). The mean serumFSH and E2 level in exposure female rats were higher than that of the control group (P<0.01), and there was a dose-effect relationship(FSH: female, rs=0.525, P<0.01, male, rs=0.363, P<0.05; E2: female, rs=0.398, P<0.01, male, rs=0.419, P<0.05) . The serum TSH level were increasing along with pesticide dose going up (rs=0.329, P<0.01); Lymphocyte translation rates are lower than the control group(p<0.01), and there was a dose-effect relationship (rs=-0.350, P<0.01). Ambivert grainy cell phagocytosis rates of exposure groups were higher than that of the control group (P<0.01) and there was a dose-effect relationship(rs=0.284, P<0.05). The mean serum IgG level were lower than the control group (P<0.01 ) and there was a dose-effect relationship (rs=-0.326, P<0.01). The serum IgA level in female exposure groups were lower than that of the control group (P<0.01 ) and there was a dose-effect relationship (rs=0.360, .P<0.05).Conclusion:Our results showed that rats exposure to the combined pesticides of cypermethrin and methylparathion one month had such effects as below:â‘  In dose of 1/135 and l/30LD5o,the serum FSH, E2 and TSH increasing.â‘¡ In dose of 1/135 and 1/30LD50, serum TSH increasing, and hypothyroid weight incre- asing in female.â‘¢ In dose of 1/600, 1/135 and l/30LD50, lymphocyte translation and serum IgG decreasing; In dose of 1/135 and l/30LD50, ambivert grainy cell phagocytose and serum IgA increasing.â‘£ In dose of 1/135 and 1/30LD50, the relative weight of adrenal gland increasing in exposure groups of male rats.