The extent of histone acetylation induced by butyrate and the turnover of acetyl groups depend on the nature of the cell line.

Cells possessing widely different physiological and morphological features have been treated with substances known to stimulate the differentiation of erythroleukemia cells. Only short fatty acids are capable of causing a hyperacetylation of the core histones and of enhancing the level of an H1-like protein in Chinese hamster ovary cells. While the time courses of a butyrate-mediated acetylation are similar for all cells, the maximum histone acetyl contents are much higher for the transformed cell of a given type. A withdrawal of butyrate rapidly (within 45 min) gives rise to a 'hypoacetylated state' for fibroblasts and transformed fibroblast (epithelial) cells from which there is a slow recovery. Lymphoid cells, on the other hand, display a marked persistance of the highly acetylated forms of histone H4.