Effect of butyric short-chain fatty acids on the bioelectric and contractile activity of gastrointestinal smooth muscle tissues.

: The present study was undertaken to investigate the effect of butyric (C4) short-chain fatty acids on the bioelectric and contractile activity of smooth muscle (SM) tissues from rat and guinea-pig gastrointestinal tracts. The study was conducted in vitro on isolated SM preparations of rat gastric corpus and guinea pig taenia coli. The following methods were used: 1. Recording of bioelectric activity using the single sucrose gap method. 2. Isometric recording of smooth muscle contractility. The results showed that there was potentiation of the spontaneous bioelectric and contractile activities of SM preparations in the presence of butyrate (a salt of the butyrate short-chain fatty acid). This effect was accompanied by an increase of Ca(2+)-influx in the SM cells. The immediate cause for this process was elevation of prostaglandin F2-alpha level in the SM tissues. The present study suggested the following conclusions: 1. Butyric short-chain fatty acid increases the contractility of gastrointestinal SM preparations of experimental animals. 2. This effect is produced by the immediate action of PGF2-alpha on smooth muscles where they are found to have elevated levels in the presence of butyrate.