Metabolic changes associated with pigmentary effector activity and pituitary removal in Xenopus lævis —II. Calcium and magnesium content of the serum

Abstract

The relationship between the parathyroids and calcium metabolism has been well established. Removal of the parathyroids in mammals results in tetany accompanied by a fall in the blood calcium content (Cruickshank, Salvesen, etc.). Tetanic symptoms and their fatal consequences can be prevented in dogs by an addition of calcium lactate to the diet (Luckhardt and Goldberg) and Collip has found that parathyroid extract raises the calcium content of the blood in both normal and parathyroidectomised dogs. Later work has raised doubts as to the specificity of the calcium effect of parathyroid extract. Davies, Dickens and Dodds obtained the same effects form injections of insulin and also pituitary extracts. Contradictory results have been reported in connection with the thyroid, namely, a rise in calcium after thyroidectomy (Maxim an Vasilin), and a rise after thyroid feeding (Cahane). Mirvish and Bosman were able to produce a fall in blood calcium in rabbits both by injection of extract of suprarenal cortex and by injection of ovarian extract. Their work is in accord with that of Taylor and Caven who found a rise in serum calcium after double adrenalectomy, and that of Werner who found a rise after castration in guinea pigs and sheep.