Abstract
Summary
Hyperammonemia was induced by injection of crystalline urease intraperitoneally in normal and Mg-deficient male rats. In hyperammonemic rats, plasma Mg tended to increase and plasma phosphate fell to about 50% of control values. Total Mg and the uptake of 28Mg by the liver, brain, heart, colon, or muscle were not changed. Mg concentrations in the kidney were decreased following acute ammonia toxicity, and release of 28Mg by liver slices in vitro was not changed by previous hyperammonemia. Hyperammonemia did not alter the rate of disappearance of 28Mg from blood. Serum Mg of rats fed a Mg-deficient diet for 7 days was 50% of control, but the biochemical and toxicological responses to hyperammonemia were not markedly altered. Serum lactate, pyruvate, and α-ketoglutarate were increased in all urease-injected animals. Serum succinate was significantly lower in Mg-deficient rats. Significant changes in Mg metabolism during hyperammonemia were not observed.
The assistance of Mrs. Mabel Goetchius, Mr. John Milner, Dr. Gary Gibson, Mr. James Carroll, and Dr. Alan Wakeling in conducting these experiments was appreciated. Mg analyses were performed by Dr. H. F. Hintz. Support provided in part by a National Science Foundation predoctoral fellowship awarded to R. L. Prior.
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