Local stimulatory effect of short-chain fatty acids on the mucus release from the hindgut mucosa of rats (Rattus norvegicus).

Short chain fatty acids such as acetic, propionic and butyric acids produced by hindgut bacteria affect various intestinal functions. However, the effect of short-chain fatty acids on mucus release from the hindgut mucosa was not clear. This study tested if these acids stimulate mucus release from hindgut mucosa and if the effect of these acids is local or requires a systemic mediation. Approximately 2 ml of either a physiologic mixture of acetic, propionic and butyric acids (100, 20 and 60 mmol/l, pH adjusted to 6.1) or 180 mmol/l sodium chloride (control solution, pH adjusted to 6.1) was infused into each permanently isolated cecum of anesthetized rats (Rattus norvegicus) through the ileal stoma by hydrostatic pressure. The cecum and distal colon were removed 1 hr after the infusion. The number of mucin containing cells per crypt section was counted on histological sections of these segments. The number of mucin containing cells was smaller in the cecum (but not in the distal colon) of rats infused in short-chain fatty acids compared with that of control rats. These results indicated that short-chain fatty acids locally stimulated mucus release from hindgut mucosa.