inositol-3-4-5-trisphosphate and Hypertension--Pulmonary

inositol-3-4-5-trisphosphate has been researched along with Hypertension--Pulmonary* in 1 studies

Other Studies

1 other study(ies) available for inositol-3-4-5-trisphosphate and Hypertension--Pulmonary

ArticleYear
Dihydropyridine Ca(2+) channel blockers increase cytosolic [Ca(2+)] by activating Ca(2+)-sensing receptors in pulmonary arterial smooth muscle cells.
    Circulation research, 2013, Feb-15, Volume: 112, Issue:4

    An increase in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) in pulmonary arterial smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important stimulus for PASMC proliferation and pulmonary vascular remodeling. The dihydropyridine Ca(2+) channel blockers, such as nifedipine, have been used for treatment of idiopathic pulmonary arterial hypertension (IPAH).. Our previous study demonstrated that the Ca(2+)-sensing receptor (CaSR) was upregulated and the extracellular Ca(2+)-induced increase in [Ca(2+)](cyt) was enhanced in PASMC from patients with IPAH and animals with experimental pulmonary hypertension. Here, we report that the dihydropyridines (eg, nifedipine) increase [Ca(2+)](cyt) by activating CaSR in PASMC from IPAH patients (in which CaSR is upregulated), but not in normal PASMC.. The nifedipine-mediated increase in [Ca(2+)](cyt) in IPAH-PASMC was concentration dependent with a half maximal effective concentration of 0.20 µmol/L. Knockdown of CaSR with siRNA in IPAH-PASMC significantly inhibited the nifedipine-induced increase in [Ca(2+)](cyt), whereas overexpression of CaSR in normal PASMC conferred the nifedipine-induced rise in [Ca(2+)](cyt). Other dihydropyridines, nicardipine and Bay K8644, had similar augmenting effects on the CaSR-mediated increase in [Ca(2+)](cyt) in IPAH-PASMC; however, the nondihydropyridine blockers, such as diltiazem and verapamil, had no effect on the CaSR-mediated rise in [Ca(2+)](cyt).. The dihydropyridine derivatives increase [Ca(2+)](cyt) by potentiating the activity of CaSR in PASMC independently of their blocking (or activating) effect on Ca(2+) channels; therefore, it is possible that the use of dihydropyridine Ca(2+) channel blockers (eg, nifedipine) to treat IPAH patients with upregulated CaSR in PASMC may exacerbate pulmonary hypertension.

    Topics: Animals; Calcium Channel Blockers; Calcium Channels, L-Type; Calcium Signaling; Cells, Cultured; Cytosol; Disease Progression; Humans; Hypertension, Pulmonary; Inositol Phosphates; Male; Monocrotaline; Myocytes, Smooth Muscle; Naphthalenes; Nifedipine; Pulmonary Artery; Rats; Rats, Sprague-Dawley; Receptors, Calcium-Sensing; Recombinant Fusion Proteins; Signal Transduction; Transfection; Up-Regulation; Vasoconstriction

2013