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Coupling between stretch‐activated channels and ryanodine receptors in vacsular smooth muscle cells.
Author(s) -
Savineau JeanPierre,
Gilbert Gillaume,
Ducret Thomas,
Marthan Roger,
Quignard JeanFrançois
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.922.5
Subject(s) - ryanodine receptor , calcium , vascular smooth muscle , chemistry , pulmonary artery , medicine , calcium signaling , pulmonary hypertension , smooth muscle , microbiology and biotechnology , endocrinology , anatomy , biology
Resistance arteries constrict in response to mechanical stress a phenomenon called “the myogenic response” that is inherent to vascular smooth muscle cells (SMC) properties. In the present study, we investigated the signaling pathway of this response both in physiological and pathological conditions (i.e. pulmonary hypertension using chronically hypoxic and monocrotaline‐treated rats). Stretching the membrane of pulmonary artery smooth muscle cells (PASMC) either via the pressure in the patch clamp pipette or a hypo osmotic shock, induced Ca2+ influx through stretch‐activated channels (SAC) which subsequently activated (1) BKCa channels, (2) RyR allowing an amplification of the calcium increase. Immunolabelling of RyR revealed that the three RyrR isoforms (Ryr‐1, RyR‐2, RyR‐3) were expressed in PASMC but with different subcellular segregation of calcium stores according the physiological status of vessels (control vs hypertensive). Indeed, calcium influx trough SAC was amplified by only subplasmalemnal RyR‐1 in PASMC from control rats while the other RyR subtypes were also involved in this amplification in PASMC from pulmonary hypertensive rats Altogether, these data suggest that SAC and RyR are necessary to this response and spatial organization of RyR and calcium stores in PASMC are important for cell signaling and response to stretch and thus in pulmonary hypertension.