Title: Lipid Peroxidation, Antioxidant Enzymes Activities in Testis, and Spermatotoxicity of Rats During Short-Term Exposure to Atrazine
Abstract: Background: Atrazine is a chloro-s-triazine herbicide that has been in used worldwide for over 4 decades now, particularly in the United States. Emerging data have implicated atrazine as an endocrine disruptor in mammals. However, information on its mechanism of action remain unknown. Objective: The aim of this study was to evaluate the acute effects of atrazine on the testicular oxidant/antioxidant systems and on some spermatologic parameters in rats. Materials and Methods: 30 inbred adult male Wistar rats of initial body weights ∼165 g were randomly divided into 3 groups with 10 animals per group and their initial body weights recorded along with a record of their daily feed intake. Animals of each group were treated with atrazine by gavages at a dose of 0 (control), 120, or 200 mg/kg body weight for 7 days. At 1 day after the last day of treatment, all the animals were killed by cervical dislocation, and paired testes and epididymides were dissected out quickly and washed in 1.15% KCl (ice-cold), pat dried, and the wet weight taken in an electrical monopan balance. One of the testes (left) was fixed in Bouin's fluid for histological evaluations and the other (right) was used for the biochemical study. Data were analyzed using the Student t test followed by ANOVA at P<.05. Results: The results indicate a decrease in the terminal body weight and food consumption only in the high-dose group. Testicular and epididymal sperm number and spermatozoa viability and motility in atrazine-treated groups decreased significantly. Therefore, atrazine treatment provoked a significant decrease in daily spermatozoal production (expressed as number of sperm per gram testis). The induction of abnormal sperm was increased by atrazine. These effects were seen in a dose-dependent manner.Tabled 1ParameterControl120 mg/kg200 mg/kgMotility (%)83 ± 2.74aDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.56 ± 5.48bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.44 ± 5.37cDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.TSN (×106/g testis)79.4 ± 1.34aDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.51 ± 1bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.48.4 ± 3.58cDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.ESN (×106/mL)135.34 ± 5.46aDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.106.65 ± 6.32bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.98.7 ± 4.81cDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.Viability (%)92.6 ± 5.13aDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.86 ± 6.52bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.84 ± 9.62bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.Abnormal sperm (%)5.44 ± 1.08aDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.9.3 ± 0.52bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.12.47 ± 1.88cDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.DSP (107/g testicular parenchyma)1.47 ± 0.17aDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.1.32 ± 0.1bDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.1.13 ± 0.14cDifferent letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number.Note: Values are mean ± SD of 10 animals per group.a,b,c Different letters within the same line signify significant (P<0.05) differences among the groups. DSP = daily spermatozoal production; TSN = testicular sperm number; ESN = epididymal sperm number. Open table in a new tab Note: Values are mean ± SD of 10 animals per group. Although there were no significant effects on lipid peroxidation, superoxide dismutase (SOD) and catalase (CAT) activities, and H2O2 generation in the atrazine groups, glutathione (GSH) and glutathione-S-transferase (GST) activities in the testis after the last day of treatment showed a significant increase vs. control.Tabled 1ParameterControl120 mg/kg200 mg/kgMalondialdehyde (μmol/g tissue)21.43 ± 4.5123.4 ± 3.2724.72 ± 4.63Superoxide dismutase (nmol epinephrine oxidized/min/mg protein)23.39 ± 9.121.53 ± 9.620.22 ± 5.94Catalase (μmol H2O2 consumed/min/mg protein)340.51 ± 27.86337.3 ± 28.8326.63 ± 18.33GSH (μg/mL/mg protein)4.33 ± 1.315.41 ± 1.25∗∗7.29 ± 1.63∗GST (μmol GSH-CDNB conjugate formed/min/mg protein)0.97 ± 0.141.34 ± 0.86∗∗3.04 ± 1.12∗H2O2 generation (μmol/min/mg protein)10.15 ± 6.110.24 ± 2.4210.46 ± 1.26Final body weight (g)161.25 ± 25.76a153 ± 25.72133 ± 21.05bFood intake (g/day)231 ± 22.47216 ± 15.57∗∗184.65 ± 26.43∗Note: Values represent mean ± SD of 10 testes/group. P<.05: ∗versus control; ∗∗versus 200 mg atrazine/mg. Open table in a new tab Note: Values represent mean ± SD of 10 testes/group. P<.05: ∗versus control; ∗∗versus 200 mg atrazine/mg. The dose and duration of treatment was inadequate to induce derangement of the seminiferous tubules but was sufficient to disrupt spermatogenesis. Conclusions: This study has added the information that oral atrazine exposure contributes to alterations in spermatologic parameters without significant effects on the parameters of oxidative stress. Possibly, atrazine may not have a direct effect on the seminiferous epithelium. Furthermore, it seems that the conjugation of atrazine to GSH appears more responsive to the metabolism of atrazine than to the testicular oxidative system. This may be secondarily related to the restricted food intake.