Abstract: ObjectiveTo investigate the effect of varied hyperglycemia and durations on preventing peripheral neuropathy (PN) with methylcobal in diabetic rats.Methods80 Sprague Dawley rats were selected and randomly chosen 16 as normal control (NC) group, others 64 animals as diabetic model induced by alloxan. The model rats were evenly divided into relatively good control (GC) group and relatively poor control (PC) group based on levels of hyperglycemia regulated with exogenous insulin. 16 rats of each GC/PC group were intramuscularly injected with methylcobal (500 μg/kg). The sensory nerve conduction velocity (SNCV), motor nerve conduction velocity (MNCV) and evoked potential amplitute (EPA) of sciatic nerve of rats were detected by evoked electromyogram respectively at 2nd, 8th and 12th week after onset of diabetes. Fructosamine in serum was also detected.ResultsThe rats injected with methylcobal had a significantly delayed reduction of SNCV, MNCV and EP in GC group (fructosamine,1.0 mmol/L) than that in PC group (fructosamine, 1.2 mmol/L) ( P<0.05～0.01). Up to 8th week after onset of diabetes, there was no obvious difference in physioelectroparameters between the GC group and NC group. At 12th week after onset of diabetes, physioelectroparameters in the PC group fell to the level of non-methylcobal injected group. No effect of methylcobal on blood glucose revealed in any groups ( P>0.05).ConclusionMethylcobal has a beneficial effect on delaying the onset of diabetic PN, and is of high efficacy with a good control of diabetic state, especially at early stage.

Key words: diabetes, methycobal, peripheral neuropathy, rat