Effect of ethephon exposure on sperm quality in adolescent male SD rats / 中华实用儿科临床杂志

ABSTRACT

Objective:To investigate the effect of ethephon exposure on sperm quality of adolescent male SD rats and the influence mechanism.Methods:A total of 40 45-day-old male SD rats were divided into control group and low, middle and high experimental groups according to the random number table method, 10 rats in each group.The said 4 groups were given 9 g/L normal saline, 100 mg/kg, 200 mg/kg, and 400 mg/kg ethephon aqueous solution for 28 days, respectively.One epididymal tail was taken to prepare sperm suspension, the sperm concentration and motility were detected.The testis and epididymis tissues were stained with HE, and their pathological changes were observed under light microscope.The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the malondialdehyde (MDA) content in the testis were detected.Enzyme linked immunosorbent assay kit was used to mea-sure the epididymal α-glucosidase activity, L-carnitine (LC) content, nuclear factor erythroid 2-related factor 2 (Nrf2) and organic cation transporter 2 (OCTN2) expression levels.Then the oxidative damage caused by ethephon to epididymis was evaluated.SPSS 26.0 software was used for data analysis.Data were compared by One- way ANOVA among groups and LSD method between 2 groups. Results:The sperm concentration of the control group, low, medium and high dose groups were (40.21±1.94)×10 9/L, (35.23±2.53)×10 9/L, (23.61±2.62)×10 9 /L, and (18.86±2.16)×10 9 /L, respectively.The sperm activity rate were (70.98±3.01)%, (57.96±3.75)%, (45.71±2.41)%, and (31.23±2.26)%, respectively.The concentration and vitality of epididymal sperms in the experimental group were significantly lower than those in the control group (all P<0.01). In the control group, low, medium and high dose groups, the SOD activity were (46.48±2.21) U/mg prot, (38.49±2.56)U/mg prot, (33.80±1.73) U/mg prot, and (27.65±2.05) U/mg prot, respectively.The GSH-Px activity in said 4 groups were (21.41±1.95) U/mg prot, (17.32±1.28) U/mg prot, (15.09±0.94) U/mg prot, and (14.08±1.23) U/mg prot, respectively.The MDA content in said 4 groups were (1.41±0.09) nmol/mg prot, (1.59±0.09) nmol/mg prot, (1.81±0.09) nmol/mg prot, and (2.16±0.14) nmol/mg prot, respectively.Compared to the control group, the experimental groups had significantly lower SOD and GSH-Px activities and significantly higher MDA content (all P<0.05). α-glucosidase levels in the control group, low, middle and high experimental groups were (15.46±0.71) U/mL prot, (12.95±0.72) U/mL prot, (11.34±0.65) U/mL prot, and (8.76±0.60) U/mL prot, respectively.LC levels in the control group, low, middle and high dose groups were(6.21±0.31) μg/L, (5.89±0.13) μg/L, (5.02±0.12) μg/L, (4.38±0.07) μg/L, respectively, compared with those of the control group, the concentration of α-glucosidase and LC in experimental groups decreased significantly (all P<0.01). The expression levels of Nrf2 in epididymis of the control group, low, middle and high dose groups were (1.34±0.05) ng/L, (1.25±0.04) ng/L, (1.08±0.06) ng/L, (0.92±0.04) ng/L, respectively; the expression levels of OCTN2 in epididymis of the control group, low, middle and high dose groups were (4.55±0.12) ng/L, (4.23±0.11) ng/L, (3.20±0.24) ng/L, (2.59±0.05) ng/L, respectively, compared with those of the control group, the expression levels of Nrf2 and OCTN2 in experimental groups decreased significantly (all P<0.01). Conclusions:Ethephon exposure leads to excessive generation of reactive oxygen and oxidative stress in reproductive organs.Ethephon exposure may activate the Keap1-Nrf2/ARE signal pathway, resulting in a decrease in the number, vitality and quality of sperms, and impaired fertility.