[Acceleration of muscle regeneration by nucleotide administration. Experimental morphometric studies].

Morphometric studies of the peroneus longus muscle as well as of the soleus muscle were performed 20, 40 and 60 days after crush injury of sciatic nerve and continuous administration of nucleotides. 96 female Wistar rats were used in the experiments. Under ether anesthesia a crush injury was performed on the right sciatic nerve. 53 rats were injected daily with nucleotides (uridine monophosphate [UMP], cytidine monophosphate [CMP] or UMP plus CMP [UMP/CMP], respectively), and 43 control animals were given injections of saline. Morphometric studies of right peroneus longus and soleus muscles were performed with the aid of a semiautomatic technique to measure muscle fibre diameters. After 20 days there were no differences between mean muscle fibre diameters. 40 days after the beginning of the experiments semiautomated morphometry revealed an increase of type II fibre diameters in the UMP/CMP group. There were enlargements of type II fibres in the UMP and the CMP group after 60 days. At the same time larger diameters of type I fibres were found in the UMP/CMP group (trend) and in the UMP group. In conclusion the results presented here indicate, that the administration of nucleotides possibly represents a new opportunity for the treatment of traumatic nerve and muscle lesions.