[Studies on the half-life of C-terminal parathyroid hormone in chronic renal failure].

: Subtotal parathyroidectomy (PTX) was performed for patients with hyperparathyroidism associated with chronic renal failure, and from sequential determination of PTH after PTX, the half-life of 2 different C-PTH was calculated. The half-life (T 1/2) of 46 approximately 84 PTH and 65 approximately 84 PTH was 18.1 +/- 3.9 and 14.0 +/- 2.2 hours (Mean +/- SD) respectively. Half-life of both C-PTH was markedly prolonged compared with that (30 approximately 60 minutes) of healthy subjects. It is considered that the longer half-life of 46 approximately 84 PTH than 65 approximately 84 PTH might be attributed to the difference of molecular weight, degrading enzymes and operative procedures. Determined value of C-PTH in chronic renal failure should be evaluated in consideration of prolonged metabolic clearance of C-PTH.