The effect of ethanol on histone glycation in diabetic rats

The glycation of liver histones was studied in rats with streptozotocin-ind uced diabetes, in ethanol (EtOH)-treated rats, and in EtOH-treated diabetic rats. In diabetes, the conditions of glucose-protein addition are more fav ourable extracellularly in serum and in erythrocytes than in the nucleus. T his is indicated by the increased level of serum fructosamine and by the hi gh level of glycated haemoglobin, while the glycation of intracellular hist one is decreased. In the serum of diabetic rats, we found a relatively high acetaldehyde level, which resulted in elevated histone fluorescence. Fluor escence is an accepted marker of advanced glycation end-product (AGE), the intensity of which, according to our experiments is related not to the leve l of serum glucose, but to the level of acetaldehyde. The data obtained wit h histone proteins in diabetic rats treated with EtOH are in good agreement with the results of our earlier in vitro experimental results obtained wit h H1 histone: the reaction of the two aldehydes (glucose and acetaldehyde) in combination gives a lower glycohistone value than they do separately.