Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Role of sarcoplasmic reticulum in regulation of tonic contraction of rabbit basilar artery
Autore:
Szado, T; McLarnon, M; Wang, XD; van Breemen, C;
Indirizzi:
Univ British Columbia, Dept Pharmacol & Therapeut, Vancouver, BC V6T 1Z3, Canada Univ British Columbia Vancouver BC Canada V6T 1Z3 ver, BC V6T 1Z3, Canada Univ British Columbia, Vancouver Vasc Biol Res Ctr, Vancouver, BC V6T 1Z3,Canada Univ British Columbia Vancouver BC Canada V6T 1Z3 uver, BC V6T 1Z3,Canada
Titolo Testata:
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
fascicolo: 4, volume: 281, anno: 2001,
pagine: H1481 - H1489
SICI:
0363-6135(200110)281:4<H1481:ROSRIR>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Soggetto:
SMOOTH-MUSCLE CELLS; TRANSIENT OUTWARD CURRENTS; CA2+-ACTIVATED K+ CHANNELS; GUINEA-PIG; CA2+ CHANNELS; CEREBRAL-ARTERIES; URINARY-BLADDER; CALCIUM SPARKS; MYOCYTES; RAT;
Keywords:
cerebral artery; spectrofluorometry; calcium; buffering;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
45
Recensione:
Indirizzi per estratti:
Indirizzo: van Breemen, C Univ British Columbia, Dept Pharmacol & Therapeut, 2176 Hlth Sci Mall, Vancouver, BC V6T 1Z3, Canada Univ British Columbia 2176 Hlth Sci Mall Vancouver BC Canada V6T 1Z3
Citazione:
T. Szado et al., "Role of sarcoplasmic reticulum in regulation of tonic contraction of rabbit basilar artery", AM J P-HEAR, 281(4), 2001, pp. H1481-H1489

Abstract

Superficial sarcoplasmic reticulum (SR) regulates smooth muscle force development directly by Ca2+ release and removal to and from the cytoplasm (Somlyo and Somlyo. J Cardiovasc Pharmacol 8, Suppl 8: S42-S47, 1986) by buffering Ca2+ influx and contributing to Ca2+ extrusion (Mueller and van Breemen. Nature 281: 682-683, 1979) and indirectly by releasing Ca2+ near Ca2+-activated K+ channels (K-Ca) to hyperpolarize the plasma membrane (Bolton and Imaizumi. Cell Calcium 20: 141-152, 1996 and Nelson et al. Science 270: 633-637, 1995). In the rabbit basilar artery, relative contributions of directeffects and those mediated through activation of K-Ca were evaluated by measuring force and intracellular Ca2+ concentration ([Ca2+](i)) in response to the SR-depleting agents thapsigargin and ryanodine and the large conductance K-Ca (BKCa) blockers iberiotoxin (IbTX) and tetraethylammonium ion (TEA). A large contraction was observed in response to K-Ca blockade with either 3 mM TEA or 100 nM IbTX and also after addition of 10 muM ryanodine or 2muM thapsigargin. When K-Ca was blocked first with TEA or IbTX, subsequentaddition of thapsigargin or ryanodine also increased force. Measurements of fura 2 fluorescence showed parallel increases in [Ca2+](i) in response tosequential blockade of sarco(endo)plasmic reticulum Ca2+-ATPase and K-Ca regardless of the order of application, It appears that a significant fraction of K-Ca remains activated in the absence. of SR function and that SR contributes to relaxation after blockade of K-Ca. We found that depletion of SR before stimulating Ca2+ influx through voltage-gated Ca2+ channels markedly reduced force development rate and that thapsigargin abolished this effect. We conclude that the SR of rabbit cerebral arteries modulates constriction by direct and indirect mechanisms.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 10:14:11