PARATHYROID HORMONE AND PHOSPHATE HOMEOSTASIS IN MAN

Publisher Website
Google Scholar
Abstract
To determine whether parathyroid hormone is required for renal response to phosphorus loading, the effects of ingestion of 3100 mg of P daily for 3 days were compared in 5 treated hypoparathyroid patients and 5 normal control subjects of comparable age and sex. In both normal and hypoparathyroid subjects the response to P loading was characterized by an increase in urinary excretion of P without a concomitant increase in the rate of glomerular filtration of P. Some mechanism other than changes in rates of parathyroid hormone secretion probably accounts for renal responses to changes in P intake. The timing of urine and serum collections with regard to food intake and the total amount of P in the diet were found to affect the assessment of renal handling of P. The finding that a 3-day period of oral P loading did not increase the serum P level in the hypoparathyroid patients suggests that P restriction is not always necessary in the treatment of hypoparathyroidism. The addition of one more condition to the list of those that may affect the percentage of renal tubular resorption of P in no way decreases the usefulness of this determination in the diagnosis of hyperparathyroidism.