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CLEARANCE OF EXOGENOUS PARATHYROID HORMONE IN NORMAL AND URAEMIC MAN
Author(s) -
PAPAPOULOS S. E.,
HENDY G. N.,
TOMLINSON S.,
LEWIN I. G.,
O'RIORDAN J. L. H.
Publication year - 1977
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1977.tb01317.x
Subject(s) - medicine , endocrinology , clearance , parathyroid hormone , immunoradiometric assay , hormone , amino terminal , clearance rate , renal function , kidney , chronic renal failure , radioimmunoassay , chemistry , urology , calcium , peptide sequence , biochemistry , gene
SUMMARY 1. The clearance of unlabelled bovine parathyroid hormone (BPTH) was studied after injection or infusion of the hormone into ten normal subjects and six patients with chronic renal failure (two of whom had been nephrectomized). 2. The build‐up and clearance of the hormone was monitored using amino‐and carboxy‐terminal region‐specific immunoradiometric assays. 3. In the normal subjects amino‐terminal BPTH was cleared rapidly. The mean plasma half‐disappearance time (t 1/2 )was 5.5 min and the mean metabolic clearance rate (MCR) was 10.37 ml/kg/min. Carboxy‐terminal immunoreactivity was cleared less rapidly, persisting for some hours in the circulation after termination of an infusion. 4. In patients with chronic renal failure the amino‐terminal region was also cleared more rapidly from the circulation than the carboxy‐terminal region. 5. As a group, the chronic renal failure patients (with kidneys and anephric subjects) cleared amino‐terminal BPTH more slowly than the normal group (mean t 1/2 = 7.95 min and mean MCR = 4.98 ml/kg/min). The value for MCR was significantly different from that of the normal group, although there was some overlap between the values for the two groups. 6. In one of the anephric subjects studied the values for the clearance of aminoterminal immunoreactivity were within the normal range, as was the MCR. This indicates that some organ other than the kidney plays an important role in the metabolism of parathyroid hormone in man. 7. There was no correlation between t 1/2 and MCR for the normal, chronic renal failure or combined groups. 8. In the uraemic subjects the metabolic clearance rate was inversely related to plasma creatinine levels.