ISSN:
1432-1076
Keywords:
Pseudohypoparathyroidism
;
Pseudopseudohypoparathyroidism
;
1,25-dihydroxyvitamin D
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract In order to clarify the complex interrelationship between serum calcium, 1,25-dihydroxyvitamin D (1,25(OH)2D), and parathyroid hormone (PTH), and the urinary excretion of cyclic AMP (cAMP) in response to exogenous PTH in pseudohypoparathyroidism (PHP) and related diseases, we investigated 3 patients with parathyroid disorders before and after treatment with 1α-hydroxyvitamin D3 (1α-OH-D3). Low plasma 1,25(OH)2D before treatment increased after giving 1α-OH-D3 (0.1 μg/kg/day), where-as high plasma PTH measured by the C-terminal assay (C-PTH) decreased in all 3. No response in urinary cAMP was found before or after treatment in 2 patients with PHP type I, despite the fall of plasma C-PTH. However, in one patient with extremely high plasma C-PTH but normal N-PTH (measured by a homologous radioimmunoassay using 1–34 human PTH), urinary cAMP response to exogenous PTH was increased after treatment with 1α-OH-D3. We suggest that he had pseudopseudohypoparathyroidism (PPHP) with Albright's hereditary osteodystrophy and a partial deficiency of renal 1α-hydroxylase. In this patient secondary hyperparathyroidism is thought to be due to 1,25(OH)2D deficiency, and the decreased responsiveness to exogenous PTH before treatment due to excess PTH occupying renal receptors.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00442101
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