The effect of desiccated thryroid, irradiated ergosterol and ammonium chloride on the excretion of calcium in rats

Abstract

The administration of 2 grains of desiccated thyroid daily, by mouth, to adult rats, led to a marked increase in Ca excretion and the establishment of a negative Ca balance. The fecal excretion of Ca became approximately constant at a new level after 12-15 days of thyroid feeding, while the metabolic rate increased progressively throughout the exps. The serum Ca was not elevated. The administration of irradiated ergosterol, in doses of 10,000 international units or more daily, by mouth, to rats receiving desiccated thyroid, reduced the fecal and increased the urinary excretion of Ca, and partly or wholly corrected the neg. Ca. balance. Smaller doses were comparatively ineffective. The administration of 250 mgm. of NH4Cl daily, by mouth, to normal rats led to a marked increase in the urinary excretion of Ca, with little influence upon the fecal excretion.