Etiology of hyperparathyroidism and bone disease during chronic hemodialysis. 3. Evaluation of parathyroid suppressibility.
Parathyroid function was assessed by calcium infusions (4-8 h) in 16 patients with chronic renal insufficiency being treated by long-term hemodialysis. The concentrations of two immunoreactive species of parathyroid hormone in plasma (iPTH-9, mol wt 9500; iPTH-7, mol wt 7000) were estimated by radioimmunoassays utilizing two relatively specific antisera. Control values of the smaller species, iPTH-7, were uniformly high, whereas values of iPTH-9 were normal in 12 of 19 studies. Response of iPTH-7 to calcium infusions was variable, with significant decreases occurring only five times in 27 infusions. Concentrations of iPTH-9, however, decreased during every calcium infusion. In contrast to these acute responses, five of six patients studied during periods of dialysis against both low (< 6 mg/100 ml) and high (7-8 mg/100 ml) calcium concentrations in the dialyzate showed a decrease in values of iPTH-7 during the period of dialysis against the higher calcium concentration. It is concluded that plasma concentrations of iPTH-9 reflect primarily the moment-to-moment secretory status of the parathyroid glands, while concentrations of iPTH-7 reflect more closely chronic parathyroid functional status. It is further concluded that the failure of iPTH-7 to decrease during induced hypercalcemia should not be equated with autonomy of parathyroid gland function.
D000818:Animals; D001847:Bone Diseases / Q000209:etiology*; D002118:Calcium / Q000008:administration & dosage / Q000097:blood; D002417:Cattle / Q000276:immunology; D002850:Chromatography, Gel; D005942:Gluconates / Q000008:administration & dosage; D006801:Humans; D006961:Hyperparathyroidism / Q000209:etiology*; D007106:Immune Sera; D007456:Iodine Isotopes; D007676:Kidney Failure, Chronic / Q000628:therapy; D008722:Methods; D008970:Molecular Weight; D010280:Parathyroid Glands / Q000503:physiopathology; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D011863:Radioimmunoassay; D006435:Renal Dialysis / Q000009:adverse effects*; D013054:Spectrophotometry, Atomic; D013552:Swine / Q000276:immunology; D013997:Time Factors
D005942:Gluconates; D007106:Immune Sera; D007456:Iodine Isotopes; D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium