Parathyroid hormone (PTH) interacts in target tissues with a G protein-coupled receptor (GPCR) localized in the plasma membrane. Although activation of GPCR can elicit rapid stimulation of cellular protein tyrosine phosphorylation, the mechanism by which G proteins activate protein-tyrosine kinases is not completely understood. In the present work, we demonstrate that PTH rapidly increases the ...

We report the consequences of prolonged treatment with recombinant human parathyroid hormone (1-34) (PTH) in male and ovariectomized female rats with mature skeletons. Intact male and osteopenic, ovariectomized, female F-344 rats were evaluated after 1 year of treatment with 0, 8, or 40 microg/kg/day s.c. PTH. Males and females were about 6 months of age at study initiation; females were ovarie...

1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) concentrations have been found to be decreased in diabetic humans and rats. To investigate further the regulation of plasma Ca in diabetes, first we measured Ca(2+), P, Mg, parathyroid hormone(1-34) (PTH), and total and free 1,25(OH)(2)D(3) in male spontaneously diabetic rats 7 and 28 days after the onset of glycosuria. Secondly, we studied changes i...

Thiazide diuretic drugs act in the distal convoluted tubule (DCI) to inhibit a Na Cl cotransporter and enhance reabsorption of luminal calcium. The density of receptors for thiazides in the rat DCI is known to be increased by adrenocortical steroids, furosemide, and bendroflumethiazide, but decreased by ischemia. Because the DCI is a physiologic site of action by calcitonin and parathyrold horm...

several important points that deserve comment. The primary objective of our paper was to report the results of a standard two-year rat carcinogenicity study conducted with recombinant full-length human PTH (1-84) to comply with international regulatory guidelines. Dr. Vahle et al. are correct that our study did not directly compare the carcinogenic potential of PTH (1-84) and PTH (1-34), that i...

article is a good review of the efficacy of the first parathyroid hormone to treat osteoporosis, PTH 1-34, including the limits of that efficacy. We would like to bring attention to the fact that there is a primary safety issue (the induction of osteosarcomas in a rat carcinogenicity study) related to the use of PTH 1-34, which was discussed at some length in the article by Neer et al. 2 In tri...

The aim of the current study was to determine the effect of parathyroid hormone (PTH) 1‑34 on cartilage degeneration, and the association between PTH 1‑34 and factors associated with the Wnt/β‑catenin pathway following anterior cruciate ligament and medial meniscectomy‑induced osteoarthritis (OA) in rats. A total of 64 Sprague‑Dawley rats were randomly divided into the following four groups: Sh...