EVIDENCE FOR A DUAL ACTION OF PARATHYROID EXTRACT IN MAINTAINING SERUM CALCIUM AND PHOSPHATE LEVELS1

Abstract

The influence of nephrectomy upon the action of parathyroid extract was studied in rats. This extract was administered to normal and parathyroid deficient rats which had been nephrectomized in a 2-stage operation. Both serum phosphate and serum Ca values were detd. Nephrectomy appeared to nullify all effects of parathyroid extract upon serum phosphate levels. However, the effect of the extract on serum Ca, though somewhat suppressed, was still apparent. Not only did the parathyroid extract prevent a further decrease in serum Ca in the nephrectomized parathyroid-deficient rat, but when 200 USP units were administered over a 24 hour period following removal of the last kidney, a definite rise in serum Ca was noted. Due to these observations, it is concluded that for its normal function, the parathyroid extract has a direct and independent effect on both Ca and phosphate metabolism.