Effect of parathyroid hormone on total phosphate and inorganic phosphate in blood, plasma, and urine of domestic fowl.
Previous work has shown that parathyroid hormone causes the kidneys of domestic fowl to secrete inorganic phosphate (Pi) into the urine. Secreted Pi is not derived directly from plasma Pi. The objective of the present study was to determine if direct or indirect correlations exist between the urinary Pi excretion rate and the concentration of phosphate in plasma or whole blood. Parathyroid hormone dissolved in gelatin carrier vehicle was injected into immature domestic fowl to cause net renal Pi secretion. Control birds were injected with carrier vehicle alone, resulting in net Pi reabsorption. Urine, plasma, and whole blood samples obtained during net Pi secretion were compared with samples obtained during net Pi reabsorption. Each sample was assayed for total and inorganic phosphate. Neither time course nor point by point comparisons of individual samples provided any evidence that secreted Pi is derived from organic phosphate in plasma or whole blood. These experiments suggest that phosphate pools within the kidneys may serve as a source for the Pi that is secreted in response to parathyroid hormone.
D000818:Animals; D001769:Blood / Q000378:metabolism; D002645:Chickens / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate / Q000662:veterinary; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D010710:Phosphates / Q000097:blood / Q000378:metabolism* / Q000652:urine; D010949:Plasma / Q000378:metabolism
D010281:Parathyroid Hormone; D010710:Phosphates