Essential fatty acid treatment prevents nerve ischaemia and associated conduction anomalies in rats with experimental diabetes mellitus.

In rats with 6 weeks streptozotocin-diabetes there was a 53% reduction in sciatic nerve laser Doppler flux compared to controls (p < 0.01). Treatment of a parallel group of diabetic rats with evening primrose oil, by dietary admixture throughout the protocol, prevented this ischaemia (Doppler flux was 91% of evening primrose-oil-treated controls and was not significantly different). There were no differences in systemic arterial pressure. In another experiment evening primrose oil markedly antagonised the development of exaggerated resistance to anoxic conduction failure in sciatic nerves from diabetic rats. The resistance to anoxia of nerves from non-diabetic rats was also reduced by evening primrose oil. These observations suggest that the sciatic nerves of diabetic rats with short-term streptozotocin-diabetes are markedly ischaemic and that this ischaemia is involved in the development of increased resistance to anoxic/ischaemic conduction failure in diabetic nerve. The findings also promote evening primrose oil as a potential treatment to prevent nerve ischaemia.