ED 05. Protective effect of L - Arginine on oxidative stress in cavernous tissue of diabetic rats

Objective: To explore the effects of L-Arginine (L-Arg) on oxidative stress in cavernous tissue of diabetic rats.

Methods: The diabetic model rats induced by streptozotocin were randomly divided into diabetes group and L-Arg treatment group. The normal rats were raised as normal control group. Eight weeks later, erectile function was assessed by measuring the rise in intracavernous pressure (ICP) of the rats following cavernous nerve eletrostimulation before sacrificed. The levels of Malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) in cavernous tissue were detected. The Masson staining was used to show the structure of rat penis.

Results: A significant decrease in ICP was recorded in the diabetic rats, with improvement measured in the rats receiving L-Arg. Compared with the normal control group, the levels of MDA increased remarkably and the activities of SOD decreased significantly in cavernous tissue of the diabetes group. Compared with diabetes group, the levels of MDA decreased significantly and the activities of SOD increased remarkably in cavernous tissue of the L-Arg treatment group. The Masson staining showed remarkable reduction of smooth muscle fibers and collagen fibers in DM group rats. Disrupted continuity and integrity of smooth muscles were also found. And they improved in L-Arg group rats.

Conclusions: Hyperglycemia could cause oxidative stress in the cavernous tissue of diabetic rats and this impairment could contribute to diabetic erectile dysfunction; Supplements of L-Arg could attenuate oxidative stress and improve erectile function.