The pH-dependent inhibitory action of n-butyrate on gastrointestinal epithelial cell division

The four-carbon fatty acid, n-butyrate is an inhibitor of cell division in vitro, but surprisingly in vivo n-butyrate is a stimulator of the gastroint estinal cell growth. In order to find any explanation of this discrepancy, our experiments were carried out in rumen epithelial cell (REC) and rumen c onnective tissue cell (RCTC) cultures at different pH values after n-butyra te addition, and the rate of cellular DNA synthesis was measured. The D-glu cose and Na-n-butyrate metabolism, further the Na+/H+ exchange of the cells were also determined at different pH values. It was established that the c ell division inhibitory action of n-butyrate in the REC, but not in the RCT C is a pi-I-dependent process, and the changing metabolism and transport pr ocesses of REC at different pH values can contribute in abrogating of the i nhibitory action of butyrate. (C) 2001 Elsevier Science Ltd. All rights res erved.