辛硫磷和灭多威对雄性大鼠生殖系统的联合毒性作用

Combined Toxicity of Phoxim and Methomyl on Reproductive Function in Male Rats

背景与目的:观察辛硫磷(phoxi m,Pho)和灭多威(methomyl,Met)对雄性大鼠生殖系统的联合毒性作用。材料与方法:选择健康成年雄性SD大鼠24只,按2×2析因设计随机分为4组:即Pho(1/50 LD50,25.20 mg/kg)、Met(1/50 LD50,0.47mg/kg)、Pho+Met(25.20 mg/kg Pho+0.47mg/kg Met)和阴性对照组(蒸馏水)。灌胃染毒每天1次,每周5 d,连续染毒60 d。末次染毒24 h后测量大鼠体重增长量、脏器湿重,精子参数(精子计数、活率、畸形率),血清和睾丸中氧化损伤相关判定指标:超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽S转移酶(GST)、谷胱甘肽(GSH),睾丸标志酶:酸性磷酸酶(ACP)、乳酸脱氢酶(LDH)、ATP酶,血清中雄性激素睾酮(T),睾丸及附睾组织形态等的改变。结果:辛硫磷和灭多威混配对精子数量、活率、畸形率、和睾酮存在协同作用,对血清中SOD、GSH和睾丸组织中SOD、GST、GSH、ACP及Na+-K+-ATPase等存在拮抗作用,对其它指标尚未观察到交互作用。辛硫磷和灭多威混配引起的睾丸组织形态学变化主要表现为生精小管管腔内可见脱落的各级生精细胞,部分生精小管生精细胞层数和各级生精细胞数量均减少,细胞排列疏松紊乱,管腔内成熟精子数量减少,附睾未见明显组织病理学变化。结论:辛硫磷和灭多威混配染毒对雄性大鼠生殖系统存在联合毒性作用,对精子数量、活率、畸形率和血清睾酮水平呈协同作用,对部分氧化损伤指标和睾丸标志酶呈拮抗作用。提示辛硫磷和灭多威混配后对雄性大鼠生殖系统的毒作用可能是通过影响睾丸功能、激素水平和精子发生及成熟过程,导致雄性生殖功能的降低。

BACKGROUND AND AIM: To study the combined toxic effects of phoxim(Pho) and methomyl(Met) on reproductive function in male rats.MATERIALS AND METHODS: The adult SD rats were randomly divided into 4 groups(including a control and three treated groups).Various daily dose of Pho(1/50 LD50,25.20 mg/kg),Met(1/50 LD50,0.47 mg/kg),Pho+Met(25.20+0.47 mg/kg) were given to rats by gastric gavage for 60 successive days.2×2 factorial analysis was used in the experiment.Body weight gain and organ weights were determined.Sperm counts,the spermatozoon survival rate and the aberration rate of the spermatozoon were measured.The activities of SOD,GST and the GSH and MDA level were ascertained in both serum and testiculer samples.The activities of ACP,LDH and ATP were assessed in testicular samples.The testosterone level was measured in serum samples and the histomorphology changes of testis and epididymis were examined.RESULTS: ① There was synergism between Pho and Met on the sperm counts,spermatozoon survival and aberration rates,as well as testosterone level.② There was antagonism between Pho and Met on GSH level and the SOD activity in serum;on GSH level of SOD activity and GST in testicle as well as the activity of ACP and Na+-K+-ATPase in testicle.③ Testicular pathology showed shed spermatogenic cells in seminiferoustubules,the layers and counts of spermatogenic cell reduced and disordered cellular arrangement in testicular tissue.There was no pathological changes in the epididymis.CONCLUSION: Markedly increased toxic effect of the pesticide mixture was found on sperm counts,spermatozoon survival and aberration rates and testosterone level.The combined exposure to Pho and Met can produce enhaced toxic effects on reproductive function in male rats.