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Updated: Sep 26, 2026

Focal Ca2+ Transient Detection in Smooth Muscle
Published on: June 28, 2009
Parathyroid hormone causes a transient rise in intracellular ionized calcium in vascular smooth muscle cells
1Department of Cell Biology, Tsukuba Research Laboratories, Yamanouchi Pharmaceutical Co., Ltd., Ibaraki, Japan.
Abstract:
The effect of parathyroid hormone on intracellular calcium concentration in vascular smooth muscle cells in culture was studied. Human PTH 1-34 (hPTH (1-34)) caused a transient rise in intracellular calcium in a dose-dependent manner at physiological concentrations. The effect of PTH was mimicked by dibutyryl cyclic AMP and inhibited by a PTH receptor antagonist. The effect of PTH was increased in parallel with extracellular calcium concentration and a sustained response was observed when extracellular calcium was 2 mM or higher. The PTH action was blocked by nisoldipin, a calcium antagonist, but not by ouabain, a Na, K-ATPase inhibitor. These data indicate that PTH increases intracellular calcium through its receptor via opening calcium channels. A possible role of this effect in the regulation of vascular tone is also discussed.
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