A comparison of the effects of glucose ingestion and NH<sub>4</sub>Cl acidosis on urinary calcium and magnesium excretion in man

Edward J. Lennon; Walter F. Piering

doi:10.1172/JCI106363

A comparison of the effects of glucose ingestion and NH₄Cl acidosis on urinary calcium and magnesium excretion in man

Edward J. Lennon and Walter F. Piering

Published July 1, 1970 - More info

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Abstract

Both glucose ingestion and NH₄Cl acidosis have been reported to augment urinary calcium (U_Ca V) and magnesium (U_Mg V) excretion. Both also cause acidification of the urine and an increase in renal acid excretion. To examine whether a common mechanism of action was involved, the effects of glucose ingestion and NH₄Cl acidosis on U_Ca V and U_Mg V were tested in the same subjects. Glucose ingestion caused significant increases in both U_Ca V and U_Mg V. During stable NH₄Cl acidosis, U_Ca V increased significantly, while U_Mg V was unaffected. When a glucose load was given during acidosis, the separate effects of acidosis and glucose on U_Ca V were additive, whereas U_Mg V increased less than observed during normal acid-base balance. Although renal acid excretion increased and the urine was acidified after glucose in the normal steady state, when glucose was administered during NH₄Cl acidosis urine pH rose and there was no change in renal acid excretion. We concluded that NH₄Cl acidosis and glucose ingestion reduce the renal tubular reabsorption of magnesium and (or) calcium, but they act through separate mechanisms.