Experimental observations and mathematical considerations on the mechanism of transport of uric acid across human gastric mucosa

Summary Under standardized experimental conditions it is shown that the uric acid concentration in human gastric juice is pH-dependent. The gastric uric acid concentration falls as a hyperbolic function with increasing acidity of gastric juice. Normally a concentration ratio of uric acid between gastric juice and plasma in the range of 0.2–0.4 will be found. These results are compatible with the conception of uric acid transport by means of non-ionic diffusion. In theoreticalmathematical considerations rate limiting factors on non-ionic diffusion of a weak acid from plasma into gastric juice are described.