The effect of ethanol on histone glycation in diabetic rats.

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