Chronic hypobaric hypoxia diminishes the expression of base excision repair OGG1 enzymes in spermatozoa.

Hypobaric hypoxia induces DNA damage in rat testicular cells, the production of defective spermatozoids and decreased sperm count, associated with an increase in oxidative stress. 8-Oxoguanine glycosylase (OGG1) enzymes are main members of the base excision repair (BER) system, a DNA repair mechanism. We determined the expression levels of mitochondrial and nuclear OGG1 isoforms in spermatozoa collected from cauda epididymis in rats exposed to chronic hypobaric hypoxia (CHH) for 5, 15 and 30 days. CHH attenuates OGG1 expression in a time-dependent fashion, with a greater reduction in the mitochondrial isoform OGG1-2a (p < .05). Attenuation of the BER system may contribute to DNA damage under hypoxia exposure.