Influence of short-chain fatty acids on vascular tone.

Results from research on the influence of short-chain fatty acids (SCFA) (C3-C6) on vascular tone are reported. Isolated vascular smooth muscle strips were studied in vitro and the arterial blood pressure of guinea-pigs injected with SCFA was taken. On the basis of results from these first two methods, the level of PG F2 alpha was determined by radioimmunoassay. The experiments indicate that in vitro the SCFA have spasmogenic effects which are blocked by indomethacin and aspirin and which are reduced by the inhibitor of the activating effect of PG F2 alpha, PG E2, and PG I2-SC19220. The effects of SCFA on smooth muscle strips used as a bioassay are analogous to the effects of PG F2 alpha on the same tissue. The injection of butyric acid into guinea-pigs causes hypertension which is not manifest if indomethacin pretreatment is carried out. Radioimmunoassay results indicate that the level of PG F2 alpha in the blood of animals treated with butyric acid is significantly increased.