Effect of hormonal manipulation on mRNA expression of antioxidant enzymes in the rat testis

We evaluated the effects of ethane dimethane sulfonate, an agent that selectively destroys Leydig cells, and hypophysectomy on CuZn superoxide dismutase, catalase and glutathione peroxidase mRNA levels in the testis.

A total of 18, 60-day-old adult rats were injected with ethane dimethane sulfonate (75 mg./kg.). After 3, 7, 14, 21, 30 and 50 days, respectively, the animals were sacrificed and the testes were harvested for RNA extraction. The 12 vehicle injected control rats were sacrificed at 0, 7, 21 and 50 days, respectively. Six 60-day-old hypophysectomized adult rats were sacrificed at age 66 days and the testes were harvested for RNA extraction. Antioxidant enzyme mRNA expression was assessed by Northern blot analysis using P labeled DNA probes derived from known cDNA sequences for superoxide dismutase, PHGPX (phospholipid hydroperoxide glutathione peroxidase) and catalase.

Hypophysectomy and ethane dimethane sulfonate treatment resulted in a significant reduction in testis weight compared with controls. Compared with vehicle injected controls PHGPX mRNA levels were reduced by 50% in the testes of ethane dimethane sulfonate treated rats 21 days after injection (p <0.05). Likewise testicular catalase mRNA levels were also reduced 21 and 30 days after injection by 55% and 50%, respectively (p <0.05). The 0.8 kb superoxide dismutase mRNA transcript levels were increased 30 and 50 days after injection by 80% and 60%, respectively (p <0.05). In hypophysectomized rats testicular PHGPX mRNA levels were increased 3-fold compared with age matched controls (p <0.05).

This study demonstrates that testicular antioxidant enzyme mRNA levels are altered in response to pituitary hormone and/or androgen deficiency.