Calcium and carbonate metabolism in the frog (Rana temporaria) during respiratory acidosis.

SMMSS, K. Calcium and carbonate metabolism in the frcg (Rana temporia) during respiratory acidosis. Am. J. Physiol. 2 14(3) : 627634. 1968.-Frogs (R. temporaria) contain large deposits of calcium carbonate in the endolymphatic sacs of the inner ear. Methods are described for determining the quantities of calcium and phosphate lost from frogs made acidotic with carbon dioxide (5-200/o in oxygen) and for determining the increase in base excess of the blood. The results suggest that acidosis causes a fall in the carbonate level of the blood and that the mineral deposits dissolve until the bicarbonate and pH levels of the blood are sufficient to restore the carbonate concentration back to its original value. This is taken to indicate that the blood is normally saturated with calcium carbonate and in equilibrium with the deposits in the endolymphatic sacs.