The Action of Volatile Fatty Acids on the Gastric Motor Mechanism in Dogs.

A fat splitting enzyme lipase has been demonstrated in the normal gastric secretion. Mathews 1 states that the digestion of emulsified stomach fats occurs to the extent of about 50 to 80% of the available total. Starling 2 showed that a considerable amount of fat is broken down in the stomach following a fatty meal. Evidence of fat hydrolysis was the presence in the stomach contents of a large proportion of free fatty acids. Edelstein and Czonka 3 found some volatile fatty acids present, including butyric, caproic, caprylic and acetic acids in infants’ stomachs.

Bahrdt and Bamberg 4 found that small amounts of lower volatile fatty acids, given by mouth produced increased peristalsis in the stomach as seen by fluoroscopic examination. The effect on the small intestines as reported by Bokai 5 was to increase peristalsis. Catel and Graevenitz 6 found the action of butyric acid on intestinal motility variable. In low concentrations it was sometimes stimulating, at other times inhibitory. In higher concentrations it was always inhibitory. Babkin 7 reported that fatty acids were stimulating in some portions of the intestines and inhibitory in other parts.

Carlson 8 reported the effects on gastric motility of various acids introduced into the stomach of dogs and man, but did not use the volatile fatty acids.

This work was undertaken to determine the effects of butyric, caproic, caprylic and caprinic acids on the tonus and motility of the gastric motor mechanism in dogs.

The experiments were carried out on young, healthy, female dogs having a gastric fistula.