the effect of carbaryl on the pituitary-gonad axis in male rats

background: carbaryl is a carbamate insecticide widely used to control pests in agriculture and farm. carbaryl adversely affect the reproductive endocrine systems in animals. objective: the aim of this study was to evaluate carbaryl effects on the pituitary-gonad axis in rats. materials and methods: in this experimental - analytical study, 60 adult male rats were divided into four equal groups: control, sham and experimental (1 and 2) groups that received 10 and 30 mg/kg carbaryl via intraperitoneally injection. the sham group was subjected to intraperitoneally injection with olive oil while the control group did not receive any injection. animals were sacrificed 35 days after the last treatment. tissue sections were prepared from testes to investigate possible changes occurring in spermatogenic and leydig cells. blood samples were collected in which the levels of testosterone, luteinizing hormones (lh) and follicle stimulating hormone (fsh) were measured. results: the results showed significant reduction in testes weight (p=0.042) and seminiferous diameters (p<0.001) within the experimental groups compared with control group. also, the number of germ cells, spermatocyts, spermatids and leydig cells on the testes of the experimental groups was significantly decreased (p<0.001). accordingly, significant decline in the testosterone levels (p<0.001) and increase in lh and fsh levels were observed (p<0.05). conclusion: these results demonstrated that carbaryl has capacity to exert adverse effects on fertility. therefore, have to be taken to account in applying carbaryl for any studies and or commercial use.