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Ca2+ channel-sarcoplasmic reticulum coupling: a mechanism of arterial myocyte contraction without Ca2+ influx.
- Source :
-
The EMBO journal [EMBO J] 2003 Sep 01; Vol. 22 (17), pp. 4337-45. - Publication Year :
- 2003
-
Abstract
- Contraction of vascular smooth muscle cells (VSMCs) depends on the rise of cytosolic [Ca2+] owing to either Ca2+ influx through voltage-gated Ca2+ channels of the plasmalemma or receptor-mediated Ca2+ release from the sarcoplasmic reticulum (SR). We show that voltage-gated Ca2+ channels in arterial myocytes mediate fast Ca2+ release from the SR and contraction without the need of Ca2+ influx. After sensing membrane depolarization, Ca2+ channels activate G proteins and the phospholipase C-inositol 1,4,5-trisphosphate (InsP3) pathway. Ca2+ released through InsP3-dependent channels of the SR activates ryanodine receptors to amplify the cytosolic Ca2+ signal. These observations demonstrate a new mechanism of signaling SR Ca(2+)-release channels and reveal an unexpected function of voltage-gated Ca2+ channels in arterial myocytes. Our findings may have therapeutic implications as the calcium-channel-induced Ca2+ release from the SR can be suppressed by Ca(2+)-channel antagonists.
- Subjects :
- Animals
Calcium Signaling
GTP-Binding Proteins metabolism
In Vitro Techniques
Inositol 1,4,5-Trisphosphate metabolism
Membrane Potentials
Muscle Contraction physiology
Muscle, Smooth, Vascular cytology
Muscle, Smooth, Vascular physiology
Rats
Rats, Wistar
Ryanodine Receptor Calcium Release Channel metabolism
Type C Phospholipases metabolism
Calcium Channels metabolism
Myocytes, Smooth Muscle physiology
Sarcoplasmic Reticulum metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0261-4189
- Volume :
- 22
- Issue :
- 17
- Database :
- MEDLINE
- Journal :
- The EMBO journal
- Publication Type :
- Academic Journal
- Accession number :
- 12941686
- Full Text :
- https://doi.org/10.1093/emboj/cdg432