Hot-humid season restraint stress duration on sperm indices and oxidative biomarkers on rats

Restraint stress is usually occasioned by excessive production of reactive oxygen species (ROS) thereby causing potential damage to the normal spermatozoa by inducing lipid peroxidation. This study investigated the possible time in which restraint stress induces maximum effects on sperm motility, concentration, and oxidative stress markers in male Wistar rats. Animals were randomly divided into three groups of three animals each (n=3). Group I- normal control (undisturbed), Group II- 3 h stress group, Group III- 6 h stress group.  Restraint stress was induced by placing rats in specially constructed restraint meshes for both 3 and 6 hours (between 9.00-15.00 h) for 21 days. Testes homogenate were evaluated for Malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH). The 3 h stress group showed a significant decrease in sperm motility and concentration (5.4 ± 0.24) when compared to the normal control group (10.0 ± 0.45) and 6 h stress group (7.3 ± 0.89) (P<0.05). Furthermore, there was a significant increase in SOD and CAT activities in the normal control group (3.33±0.09; 60±1.20) when compared to the 3 h and 6 h stress groups (2.13±0.09; 34±1.20) and (2.37±0.09; 54±1.2) respectively (P<0.05). Restraint stress for both 3 and 6 h induces oxidative stress which might lead to a decrease in sperm motility and concentration; however, 3 h of stress induces more oxidative damage among male Wistar rats.