Effects Of Acrylamide On The Reproductive Toxicity In Male Rats

Acrylamide is a kind of more familiar chemical materials, extensively used in the industry and the research experiment. Acrylamide, a kind of important occupation contact compound, can through skin quickly be absorbed by organism. Recently, it has been reported that starchy food cooked at high temperature can produce acrylamide. The acrylamide monomer has the potential for human exposure either through the environment or from occupational exposure. The extensive concern for the toxicity of acrylamide has arisen with the finding of acrylamide formation in some processed food. The human may also contact acrylamide by smoking. The acrylamide monomer causing several toxic effects can influence the reproduction and development in male animals, but its mechanism of action is still not clear currently. The former research more adopted acute toxicity testing through high dose, but the report about acrylamide long-term reproductive toxicity action by mouth is few. This research systematically investigated the effect of subchronic exposure to acrylamide on the male reproduction, lipid peroxidation levels and testis endocrine function of reproduction in the whole animal experiment and in vitro, to explore the effect of acrylamide on the reproduction and testis endocrine function of reproduction in male rats, to provide science the basis for the further researching acrylamide male reproductive toxicity.1. Effects of acrylamide on the reproduction in male ratsHealthy 8-week-old male Sprague Dawlay rats were randomly divided into 4 groups with 10 animals in each group. Acrylamide was administered by gavage at dosages of 0, 4, 10, 18 mg/kg.d. After 9-week acrylamide exposure, the hindlimb landing foot splay was determined and then rats in each group were killed with certain organs selected. The related organs were selected and weighed to assess the organ body ratios. The sperm morphology in the epididymis tail was detected. The activities of acid Phosphatase (ACP), alkaline Phosphatase (ALP), lactate dehydrogenase (LDH) and gamma-glutamyl transpeptidase (γ-GT) in the testis homogenate were determined. The results showed that the hindlimb landing foot splay increased markedly compared with the control group(P<0.01).The Percent of sperm vitality declined significantly compared with the control group (P<0.01) and the Percent of abnormal sperm enhanced evidently compared with the control group(P<0.05). ACP activities showed a decreasing tendency, while ALP activities revealed an increasing then a decreasing tendency. ACP and ALP activities were inhibited significantly at 18 mg/kg.d compared with the control group(P<0.05).2. Effects of acrylamide on the lipid peroxidation in male ratsHealthy 8-week-old male Sprague Dawlay rats were randomly divided into 4 groups with 10 animals in each group. Acrylamide was administered by gavage at dosages of 0, 4, 10, 18 mg/kg.d. After 9-week acrylamide exposure, rats in each group were killed with certain organs selected. The activities of glutathione peroxidase (GSHPx) and superoxide dismutase (SOD) in serum and in testis homogenate were determined respectively by spectrophotography. The levels of glutathione (GSH) and malondialdehyde (MDA) in serum and in testis homogenate were measured by spectrophotography too. The results showed that no significant changes were noted in serum GSH levels, MDA levels, GSHPx activities and SOD activities (P>0.05). But the levels of GSH and the activities of SOD in testis homogenate were significantly restrained (P<0.01), the activities of GSHPx were significantly arrested too (P<0.05). MDA, no obvious changes was examined in testis homogenate (P>0.05).3. Effects of acrylamide on the testis endocrine function of reproduction in maleHealthy 8-week-old male Sprague Dawlay rats were randomly divided into 4 groups with 10 animals in each group. Acrylamide was administered by gavage at dosages of 0, 4, 10, 18 mg/kg.d. After 9-week acrylamide exposure, rats in each group were killed with certain organs selected. The levels of the testosterone(T) and 17β-estradiol(17β-E₂) in the serum and testis homogenate by radioimmunoassay were detected respectively. Leydig cells were isolated from the testes of acrylamide-treated rats. After 24h incubation, the viability of Leydig cells was assessed by the CCK-8 method. Testosterone concentrations in the culture media of Leydig cells were also measured by radioimmunoassay after incubating Leydig cells for 24h.Based on the primary Leydig cell culture model, acrylamide exposure groups involved control (0 mmol/L), 0.1, 0.75, 4 and 8mmol/L in the culture media of Leydig cells. Leydig cell activity was measured by the CCK-8 method, too. The results showed that 17β-E₂ levels in serum and in testis homogenate were not significantly changed, whereas T levels in serum and in testis homogenate reduced significantly(P <0.01). Acrylamide treatment increased the level of Leydig cells, isolated from the testes of acrylamide-treated rats, death(P<0.01).Testosterone concentrations in the cultured media of Leydig cells also decreased significantly(P < 0.01)in all acrylamide-treated groups. After Leydig cells were directly exposed to acrylamide for 24 hours, the activity of Leydig cells declined evidently(P<0.01).It is showed that subchronic exposure to acrylamide could damage the normal male potentia generandi, results in changes in some enzymes activity in the testis, significantly influence hindlimb motor coordination, break the balance of oxidation-antioxidation system in testis, Lipid peroxidation is one possible toxic mechanism caused by acrylamide, directly cause toxic effects in the Leydig cells and affect endocrine function of the testis.