Normal parathyroid hormone responsiveness of bone-derived cells from a patient with pseudohypoparathyroidism
Abstract
Pseudohypoparathyroidism (PHP) is characterized by a lack of response to parathyroid hormone (PTH); however, normal skeletal responsiveness to PTH in some patients with PHP type Ia was previously suggested on the basis of clinical observations. To test this hypothesis, we measured cyclic adenosine monophosphate (cAMP) production in response to various agonists in bone-derived osteoblast-like (OBL) cells from trabecular explants obtained from an iliac crest biopsy of a 25-year-old woman with PHP. The patient was proved to have PHP type Ia on the basis of Albright's hereditary osteodystrophy and decreased activity of stimulatory guanine nucleotide-binding protein (Gs) in erythrocytes. Responsiveness of the patient's OBL cells was compared with OBL cells from eight subjects aged 18-39 years who had no evidence of metabolic bone disease. OBL cells from the patient responded to the following agonists (expressed in multiples of elevation of cAMP, stimulated/basal, mean +/- SE, n = 3): PTH, 3.8 +/- 0.3; forskolin, 8.2 +/- 0.2; and cholera toxin, 56.8 +/- 10.0. These responses were not significantly different from those of control OBL cells: PTH, 4.5 +/- 1.1 (range 2.4-7.5); forskolin, 7.7 +/- 1.4; and cholera toxin, 57.9 +/- 16.2. The normal cholera toxin response indicated the presence of functional Gs. Bone cells from patients with PHP type Ia may exhibit a normal PTH receptor-coupled adenylyl cyclase system in vitro despite clinical evidence of impaired hormone-responsive…
How strong is the evidence?
Evidence Hub reads this as a case report, done in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.
Read the paper
Related studies
- Irisin Enhances Osteoblast DifferentiationIn Vitro
- Glucocorticoids suppress Wnt16 expression in osteoblasts in vitro and in vivo
- Interaction between Schwann Cells and Osteoblasts In Vitro
- Administration of cinnamaldehyde promotes osteogenesis in ovariectomized rats and differentiation of osteoblast in vitro
- The Effect of the Major Components of Fructus Cnidii on Osteoblasts In Vitro
- Estrogen depletion alters osteogenic differentiation and matrix production by osteoblasts in vitro
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.