In:
The Journal of Clinical Endocrinology & Metabolism, The Endocrine Society, Vol. 88, No. 5 ( 2003-05-01), p. 2250-2255
Abstract:
PTH (7–84) has antagonistic effects on the calcemic and phosphaturic actions of PTH (1–84) whole molecule (bioPTH). Human plasma contains bioPTH and PTH (7–84)-like fragments. Using bioPTH-specific and nonspecific assays, we found that the patients with pseudohypoparathyroidism (PHP) type I with PTH-resistant hypocalcemia and hyperphosphatemia had the increased plasma levels of bioPTH and PTH (7–84)-like fragments than normal subjects (26.8 ± 13.2 vs. 2.37 ± 0.75 pmol/liter, P & lt; 0.01 and 16.2 ± 8.8 vs. 0.82 ± 0.47 pmol/liter, P & lt; 0.01, respectively). Calcitriol treatment increased phosphaturic response to PTH (1–34) (P & lt; 0.05), and there was a negative correlation between phosphaturic response and the PTH levels (P & lt; 0.05). These results suggested that the increased bioPTH and PTH (7–84)-like fragment levels may be related to the impaired phosphaturic response to PTH (1–34) in PHP type I. We also examined bioPTH-calcium dynamics in PHP type Ib patients and found that set-point calcium was 0.928 ± 0.045 mmol/liter and the baseline to maximal ratio of bioPTH was 0.96 ± 0.04. Calcitriol treatment increased set-point calcium to 1.129 ± 0.028 mmol/liter (P & lt; 0.01) and suppressed baseline to maximal ratio of bioPTH to 0.35 ± 0.21 (P & lt; 0.01). These bio-PTH calcium dynamics studies revealed the maximally stimulated baseline PTH secretion in PHP type Ib and demonstrated the effects of calcitriol on PTH-calcium curve shift and the degree of relative stimulation of baseline secretion.
Type of Medium:
Online Resource
ISSN:
0021-972X
,
1945-7197
DOI:
10.1210/jc.2002-021610
Language:
English
Publisher:
The Endocrine Society
Publication Date:
2003
detail.hit.zdb_id:
2026217-6
Permalink