AB196. The long-term administration of tadalafil on STZ-induced diabetic rats with erectile dysfunction via local antioxidative mechanism

OBJECTIVE: To clarify the antioxidation role in diabetic ED treatment by a long-term administration of PDE5I. METHODS: Three groups of Sprague-Dawley rats were utilized: group N, normal control; group D, streptozotocin (STZ) induced diabetic rats as control; group D + T, STZ induced diabetic rats by the intragastric administration with tadalafil for 8 weeks. RESULTS: ICP/MAP ratio was significantly higher in group D + T than in group D. The levels of MDA decreased remarkably and the activities of SOD increased significantly of group D + T, compared with group D. The level of mitochondrial membrane potential of cavernous tissue of diabetic rats was partly recovered by tadalafil treatment for 8 weeks. The morphology changes of mitochondria were also ameliorated in group D + T. CONCLUSIONS: The long-term administration of tadalafil on diabetic rats is proven to partly lessen the oxidative stress lesion of the penis via a local antioxidative stress pathway. Early long-term dosages of tadalafil once daily maybe partly prevent rats from diabetic erectile dysfunction. To our knowledge, this is the first report to reveal the new mechanism on long-term treatment of tadalafil in diabetic ED.