On Certain Physiologic Responses to Intravenous Injection of Calcium Salts Into Normal, Hyperparathyroid and Hypoparathyroid Persons*†

Vitamin D-Resistant Rickets: The Effect of Calcium Infusion on Phosphate Reabsorption *

“…On a random diet, the baseline TRP in normal subjects in this laboratory is 85 + 3 per cent, with 95 per cent confidence limits of 77 to 93 per cent (13). The serum phosphorus increased during the infusion in every case, in agreement with previously reported data (14). The creatinine clearance remained constant or increased.…”

The relationship of parathyroid activity to pyrophosphate excretion.

“…The hypothesis that the changes in urinary pyrophosphate, illustrated for normal subjects in Table I, resulted primarily from suppression of endogenous parathyroid hormone release and decreased bone resorption rather than from secondary changes in circulating phosphate and orthophosphate excretion is strengthened by the observation that pyrophosphate excretion falls when calcium salts are administered to normal individuals despite a concomitant rise in serum phosphate (Figure 3). Whereas the coincident fall in orthdphosphate clearance under these circumstances is attributed to an increased tubular resorption of orthophosphate (27)(28)(29), the fall in urinary pyrophosphate probably reflects a decrease in bone resorption, since PTE has no direct effect on the renal excretion of pyrophosphate (Tables IV and V , Figure 5).…”

“…Short term infusion of calcium salts to these patients generally produces a rise in both serum phosphate and orthophosphate clearance (29,30). The rise in orthophosphate excretion has been attributed in the past to the rise in serum phosphorus coincident with a decreased tubular resorption of phosphate.…”

“…Schwartz (32) and Nordin, Smith, and MacGregor (33) have also noted suppression of hydroxyproline excretion in subjects with hyperparathyroidism during calcium infusion studies despite the reported insensitivity of parathyroid tumors to induced hypercalcemia (27,29). These results suggest either that some parathyroid tumors may not be completely autonomous and their secretions alterable by physiologic stimuli or that in weakly functioning tumors the remaining normal glands may be still further suppressed by induced hypercalcemia.…”

Evaluation of a standardized short-time calcium suppression test in healthy subjects: interest for the diagnosis of primary hyperparathyroidism

“…On this basis, a PTH suppression test using calcium loading has been proposed in order to differentiate PHP patients from subjects with normal parathyroid function (17). Several modalities have been described (12,(18)(19)(20)(21)(22)(23) and different markers have been proposed as phosphate clearance (24), urinary cyclic AMP (17), or immunoreactive PTH (12,18,19,(21)(22)(23). However, no standardized test is presently available.…”