Goshajinkigan increases peripheral capillary diameter in non‐diabetic and diabetic mice

Aim: Goshajinkigan (GJG) improves hyperesthesia and hypoesthesia in diabetic peripheral neuropathy (DPN) by increasing nitric oxide (NO) production. In this study, we investigated the involvement of NO in the vasodilatory effect of GJG in peripheral capillaries to clarify the mechanism related to DPN symptom improvement. Methods: GJG was orally administered to non-diabetic and streptozotocin (STZ)-induced diabetic male mice. Auricular venule and arteriole diameters were measured by video capillaroscopy. The mice were pretreated with N-G-nitro-L-arginine methyl ester (L-NAME) to assess NO involvement. Results: GJG increased venule and arteriole diameters in both non-diabetic and diabetic mice. L-NAME pretreatment inhibited GJG-induced increases in capillary diameter. Conclusion: The direct vasodilatory effect of GJG in peripheral arterioles and venules involved increased NO production.