Bile salt composition and concentration as determinants of canine gastric mucosal injury
Harmon, J.W.; Lewis, C.D.; Gadacz, T.
Surgery 89(3): 348-354
1981
ISSN/ISBN: 0039-6060 PMID: 7466625 Document Number: 169095
Qualitative and quantitative differences in bile salts could be the reason why some patients with bilious reflux into the stomach develop gastritis or gastric ulcers, whereas others do not. The hypothesis that both the composition and concentration of a bile salt solution determine the degree of damage to the gastric mucosa was examined. The effects of 2 mixtures of bile salts containing high and low levels of deoxycholate within the range of that found in man were studied. These solutions were tested on the fundic gastric mucosa in Heidenhain pouches of 5 mongrel dogs. Net acid back diffusion (NABD) was measured by a recirculating system incorporating a pH stat, and transmucosal potential difference (PD) was recorded in a standard manner. Mixtures of the taurine conjugates of the sodium salts of cholate (TC), chenodeoxycholate (TCDC) and deoxycholate (TDC) were studied at pH 2. Bile mixture A (low TDC) consisted of 10% TDC, 20% TCDC and 70% TC; mixture B (high TDC) consisted of 35% TDC, 35% TCDC and 30% TC. At 3 mM concentration, bile salt mixture B increased NABD from 54 .+-. 23 to 101 .+-. 11 .mu.eq/10 min (P < 0.05); mixture A increased NABD slightly from 66 .+-. 11 to 72 .+-. 15 .mu.eq/10 min. In the same experiments, PD was reduced 18 .+-. 2mV by mixture B, but only 10 .+-. 2mV by mixture A (P < 0.05). Thus the mixture high in TDC was more damaging than the mixture low in TDC at 3 mM concentrations. At 1 mM, neither mixture was damaging, and at 5 mM both were similarly damaging. In a 2nd series of experiments each of the 3 bile salts was tested individually at 5 mM concentration, and TDC produced greater increases in NABD and decreases in PD than either TC or TCDC. Damage to the gastric mucosa evidently depends on the concentration as well as the composition of the bile salt mixture present.