EFFECTS OF SOME ION EXCHANGE RESINS ON THE MINERAL METABOLISM OF RATS

Abstract

A variety of ion exchange resins was tested with respect to their capacities for binding cations in vivo. All of the cationic exchange resins bound some Na and K in the intestine; when fed in the hydrogen cycle they also bound some Ca. About 25% of the total capacity of the resin was utilized, with Na and K being bound in about the same ratio as in the diet. Some tests were conducted to detn. whether feeding an anionic exchange resin would increase the available capacity of a resin of the carboxylic type, but the results were equivocal. When a resin of the latter type was fed partly in the K cycle, it bound Na fairly satisfactorily, and with less net loss of alkali than when fed entirely in the H cycle. At a 10% dietary level the resins usually bound from 15 to 60% of the Na intake; differences in amts. bound could have been predicted from the rated capacities of the individual resins. Negative balances of Na, K, and Cl were observed occasionally on the resin regimes. In a 3-week feeding expt., with a diet adequate in K and Ca, but practically devoid of Na, the animals were able to maintain positive balances of all 3 elements, although the Na balances were very small. At autopsy Na and K in both serum and muscle were essentially normal. It seems likely that the resins act to relieve edema almost entirely by binding exogenous Na.