Prevention of death of axotomized hypoglossal neurones and promotion of regeneration by chitin grafting

Enhancement of rat hypoglossal nerve regeneration by chitin sheet plus gangliosides

The effects of chitin sheet interposition with and without brain gangliosides on the regeneration of hypoglossal nerve fibres was studied in the rat following resection of a 5mm length of the nerve. At 10 weeks after operation, the number of horseradish peroxidase (HRP)-labelled motor neurones, indicative of the axonal repair process, on the side treated with chitin and gangliosides was higher than on the control side (where 5mm of the nerve was simply resected). The ratios of HRP-positive neurones in the right hypoglossal nucleus (treated side)/left hypoglossal nucleus (intact side) was 0 in the 5mm-resected group, 53% in the chitin-grafted group, 88% in the ganglioside (0.2 microg)-injected group, 90% in the ganglioside (2 microg)-injected group, 91% in the chitin with ganglioside (0.2mg)-injected group, 91% in the chitin with ganglioside (2 microg)-injected group and 85% in the autograft group, respectively. There were significant differences between the 5 mm-resected group and chitin-grafted group, ganglioside-injected group, chitin with ganglioside group and autograft group, and between the chitin-grafted group and ganglioside-injected, chitin with ganglioside and autograft groups (P< 0.005, respectively). Our results indicated that the use of chitin and gangliosides stimulated the regeneration of severed motor nerve fibres. These findings suggest that chitin and gangliosides might be therapeutically useful for treatment of neuronal degeneration.