Effects of elcatonin on plasma and urine electrolytes in infant beagles

The effects of elcatonin (ECT) on the renal hemodynamics and electrolyte levels in plasma and urine were investigated in anesthetized infant beagles (3 months old) and adult beagles (9-10 months old). Intravenous injections of 50 MRC U/kg ECT did not alter the systemic blood pressure, renal blood flow, glomerular filtration rate, and urine flow in intact puppies as well as in puppies and adult dogs subjected to extirpation of the thyroid and parathyroid glands (TPTX). One hundred and twenty min after ECT injection, the plasma calcium concentration decreased by 1.06 +/- 0.15 mEq/l in intact puppies and 0.94 +/- 0.10 mEq/l in TPTX puppies, but decreased only by 0.38 +/- 0.22 mEq/l in adult TPTX dogs. The urinary calcium excretion decreased in all the puppies. The plasma phosphorus concentration decreased by 1.02 +/- 0.10 mg/dl, and the phosphorus excretion rate increased 63.6 +/- 26.4% in intact puppies; whereas the plasma phosphorus and phosphorus excretion were not altered in TPTX puppies. Diuresis and natriuresis were not obtained. These data suggest that the acute hypocalcemic effect of ECT is dependent on age and is not associated with its action on kidneys.