[Exploration of the parathyroid gland function by intake or oral calcium and phosphate (only oral intake and sequential treatment with calcium-phosphate)].

The parathyroid hormone response to the oral intake of either calcium or phosphate was explored in 10 young adults (23-28 years). First, the subjects were investigated during free running diet. They ingested a single oral dose of 500 mg of calcium (as a bag of Sandocal) and 10 days later a single oral dose of phosphate (750 mg of phosphorus as a tablet of Phosphore Sandoz Forte). Samples of blood and urine were collected before and during the 4 hours following the ingestion of either calcium or phosphate. After intake of calcium an acute response was obtained with a 58% decrease in PTH 1-84 at 1 hr (p less than 0.001) and a 33% decrease in nephrogenous cAMP (p less than 0.001). After ingestion of phosphate the response was delayed and less constant with a 25% increase in PTH 1-84 at 3 hr (p less than 0.01) and a 27% increase in nephrogenous cAMP (p less than 0.001). Then, the effects of a calcium therapy (3 daily doses of 500 mg each for 20 days) and of a subsequent phosphate therapy (2 daily doses of 750 mg each for 10 days) on the parathyroid hormone response to the administration of a single dose of phosphate were studied. On days 10, 21 and 31 baseline blood and urine samples were obtained prior to calcium and phosphate administration for measuring PTH 1-84 and nephrogenous cAMP. No significant variation was found. On days 21 (after calcium therapy) and 31 (after phosphate therapy) an oral load of phosphate was administered according to the procedure described above.(ABSTRACT TRUNCATED AT 250 WORDS)