Abstract

BACKGROUND
Diabetic neuropathy is associated with risk factors for macrovascular diseases and other microvascular complications. Alpha-lipoic acid (ALA) administration has been reported to improve metabolic abnormalities and ameliorate peripheral polyneuropathy in diabetic patients. In addition, ALA improves endoneurial nutritive neural blood flow and nerve conduction velocity in diabetic rats. But it is not clear whether ALA has a preservation effect on microvasculature in addition to the effect on intraepidermal nerve fibers (IENFs). We investigated the effect of ALA on intraepidermal nerve fiber density (numbers/mm) and cutaneous capillary length in streptozotocin-induced diabetic rats. METHODS: The rats were randomly divided into 3 groups: diabetes without diet control, diabetes with diet control, and diabetes with ALA treatment. Diabetes was induced by a single intraperitoneal injection of streptozotocin (60 mg/kg) and the effect of ALA treatment was assessed by IENF immunostained with protein gene product 9.5 and by quantification of total cutaneous capillary length with mouse anti-rat reca-1 immunostaining. RESULTS: The value of IENF density significantly increased in ALA treatment group compared with other groups (P < 0.05). Quantification of microvascularity was also significantly increased in ALA treatment group compared with other groups (P < 0.05). CONCLUSION: The results of this study suggest that ALA administration in diabetic rats may be beneficial in the prevention of peripheral neuropathy associated with improvement of microvascularity. And the symptomatic amelioration after ALA treatment may be attributed to this morphological improvement.

• Keywords: Alpha-Lipoic Acid;Diabetic Neuropathy;Intraepidermal Nerve Fiber;Microvascularity;