Objective: To establish a model of reproductive system injury in male rats at high altitude using the low-pressure hypoxic animal laboratory and study the changes in the testicular tissue, semen parameters, blood gas and oxidative stress in male rats at different altitudes.
Methods: Sixty male Wistar rats were randomly assigned to be raised on the plains (the plains group, n = 20), at an altitude of 4 000 m (the plateau model group Ⅰ, n = 20), or at an altitude of 6 000 m (the plateau model group Ⅱ, n = 20) for a spermatogenic cycle of 14 days. After establishment of the model of high-altitude reproductive system injury, the testis tissues of the rats were harvested for HE staining and observed for histopathological changes under the light microscope, and their epididymedes collected for preparation of sperm suspension and detection of sperm motility, sperm count and the percentage of morphologically abnormal sperm (MAS). The blood gas level and oxidative stress-related indexes in different groups were also measured using the serological test.
Results: With the elevation of altitude, the levels of pH and PO2 were decreased, those of PCO2, Hct, K+, Cl－ and Hb increased markedly, while that of Na+ exhibited no significant change. The model rats also showed folded spermatogenic tubule walls, thinned spermatogenic epithelia, disorderly arranged and reduced number of spermatogenic cells, and increased vascuolization in the spermatogenic epithelia, with decreased sperm motility and count, increased percentage of MAS, elevated concentration of malondialdehyde (MDA) and reduced activity of superoxide dismutase (SOD).
Conclusions: A model of reproductive system injury was successfully established in male rats at a simulated altitude of 4 000 m. With increasing of the altitude to 6000 m, oxidative damage to the testicular tissue was aggravated, sperm motility decreased, and the percentage of MAS increased, indicating that an altitude of 6 000 m may cause serious damage to the rat reproductive system.
Keywords: blood gas analysis; model; oxidative stress; rat; reproductive damage; plateau.