Rosuvastatin positively changes nerve electrophysiology in diabetic rats

OBJECTIVE: To examine the effect of rosuvastatin on peripheral nerve function in diabetic rats using electrophysiological measurements. BACKGROUND: Diabetes was induced in 5-day-old male Wistar rats by intraperitoneal (i.p.) injection of streptozotocin (STZ). As many as 45 diabetic rats were randomized to three groups: one treated with rosuvastatin (group R), another with rosuvastatin and mevalonate (group MR) and the other was untreated (group U). The data were compared with a group of normal age-matched rats i.e. control rats (group C). METHODS: Neurophysiological measurements were performed at the age of 3 months (T1) and again at the age of 8 months (T2), after 3 months of treatment. RESULTS: At T1, there was a trend to lower amplitude of compound motor action potential (CMAP) in the three diabetic groups as compared to controls, and no difference for motor nerve conduction velocity (MNCV), amplitude of sensory nerve action potential (SNAP), sensory nerve conduction velocity (SNCV) between diabetic groups and controls. At T2, the amplitude of CMAP was significantly lower in groups R and MR versus group U and control rats. MNCV was significantly and similarly decreased in the three diabetic groups; the latency of the first sensory peak (fastest sensory fibres) was significantly increased in group U but was normal in groups R and MR. CONCLUSIONS: This study shows that: 1.rosuvastatin exerts a beneficial effect on the conduction of the fastest sensory fibres;2.these effects are independent of blood pressure and lipid changes.