Removal of calcium from frog bone by peritoneal lavage, a study of parathyroid function in amphibians

Abstract

The work covered in this paper deals with experimental studies on the amphibian, Rana catesbeiana, designed to compare parathyroid function in this class of vertebrates to that found in mammals. The experimental procedures utilized the techniques of peritoneal lavage currently used in this laboratory in the study of parathyroid function in rats. The use of the amphibian has the added advantage that the animal can be maintained at temperatures approaching 0°C, permitting the study of the effect of temperature on hormonal action. Our studies indicate that parathyroid function in respect to bone is essentially the same in amphibians as in mammals, in that parathyroidectomy reduced but did not abolish the ability of frog bone to continuously supply calcium to body fluids under the conditions of peritoneal lavage. Experimental conditions which altered endogenous parathyroid activity influenced markedly the numbers of osteoclasts which were found most frequently in bones such as the coracoid and sternum rather than in the long bones of the appendages. Peritoneal lavage of frogs maintained at 4°C indicated that some sort of basic physico-chemical process exists in the frog which permits the removal of calcium at this temperature in the absence of endogenous parathyroid stimulation or increased osteoclastic function.