The Excretion of Calcium and Magnesium after Parathyroidectomy

Within the past few years evidence has gradually accumulated, both direct and indirect, indicating some definite relation, the nature of which is as yet quite obscure, between the kations of calcium salts and certain forms of muscle irritability. The observations recorded may be summarized as follows : ( I ) Abnormal muscular twitchings and contractions may be brought about in an organism by a reduction in the proportion of calcium (or magnesium) in the muscles or blood (J. Loeb) ; (2) the injection into the animal body of any salt liable to precipitate calcium causes twitchings of the muscles (J. Loeb); (3) in tetany of children, the calcium content of the brain has been found lowered (Quest); (4) infantile tetany has shown marked improvement following the administration of calcium salts (Netter) ; (5) soluble calcium salts exert a wonderful curative effect on the tetany in dogs following parathyroidectomy (MacCallum and Voegtlin). In a recent communication MacCallum and Voegtlin ~ describe a series of experiments in which they found an increased excretion of calcium in the urine and feces of parathyroidectomized dogs during tetany. They also found a decrease in the calcium content of the brain and blood of dogs in tetany as compared with normal