Cclv. the Reciprocal Relationship of Calcium

HOWLAND AND KRAMER [1923] showed that in rickets the concentration product of calcium and inorganic phosphorus falls below a certain critical level. Their work suggested a fundamental relationship between the levels of Ca and inorganic P of the blood. Bourne and Campbell [1932] by simultaneous determinations of calcium and inorganic P of the blood in rabbits have shown that the concentrations of these two substances bear a reciprocal relation to each other. Their work is fully supported by the work of Dupre and Semeonoff [1931]. On the other hand Theiler, Green and du Toit [1927] found in their extensive work on cattle that the blood-Ca remained normal even withan inorganic P of one quarter the normal figure. This contradiction might suggest that in this respect ruminants differed fundamentally from rabbits. Recent work by Auchinachie and Fraser [1932], however, on the blood of sheep fed a Ca-deficient ration has shown that an abnormally low serum-Ca may be accompanied by an abnormally high inorganic P, and that there is evidence of a reciprocal relationship between the Ca and inorganic P of the blood of sheep.