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Titolo:
ARACHIDONIC ACID-DEPENDENT PHOSPHORYLATION OF TROPONIN-I AND MYOSIN LIGHT-CHAIN-2 IN CARDIAC MYOCYTES
Autore:
DAMRON DS; DARVISH A; MURPHY L; SWEET W; MORAVEC CS; BOND M;
Indirizzi:
CLEVELAND CLIN FDN,RES INST,DEPT MOLEC CARDIOL FF10,9500 EUCLID AVE CLEVELAND OH 44195 CLEVELAND CLIN FDN,RES INST,DEPT MOLEC CARDIOL FF10 CLEVELAND OH 44195 CLEVELAND CLIN FDN,RES INST,CTR ANESTHESIOL RES CLEVELAND OH 44195
Titolo Testata:
Circulation research
fascicolo: 6, volume: 76, anno: 1995,
pagine: 1011 - 1019
SICI:
0009-7330(1995)76:6<1011:AAPOTA>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
PROTEIN-KINASE-C; RAT-HEART; SARCOPLASMIC-RETICULUM; VENTRICULAR MYOCYTES; ACTOMYOSIN MGATPASE; CALCIUM SENSITIVITY; MYOCARDIAL-CELLS; OKADAIC ACID; K+ CHANNELS; FATTY-ACIDS;
Keywords:
MYOCYTES; ARACHIDONIC ACID; ENDOTHELIN-1; PHOSPHORYLATION; MYOFILAMENTS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
50
Recensione:
Indirizzi per estratti:
Citazione:
D.S. Damron et al., "ARACHIDONIC ACID-DEPENDENT PHOSPHORYLATION OF TROPONIN-I AND MYOSIN LIGHT-CHAIN-2 IN CARDIAC MYOCYTES", Circulation research, 76(6), 1995, pp. 1011-1019

Abstract

Recent evidence has suggested that arachidonic acid (AA) may be an important signaling molecule in cardiac excitation-contraction coupling. We previously showed that AA and endothelin-1 (ET) inhibit distinct K channels via protein kinase C-dependent pathways in rat ventricular myocytes. In addition, we demonstrated that Ca2+ transients in populations of fura 2-loaded myocytes were potentiated by AA and ET via activation of protein kinase C. In this study, we have used suspensions of [P-32]orthophosphate (P-32(i))-labeled rat ventricular myocytes to study the effects of AA and ET at the level of the myo filaments. After a10-minute incubation of the labeled cells with phorbol 12-myristate 13-acetate (PMA), AA, or ET in the presence or absence of the protein kinase C inhibitor calphostin C, the myofibrillar proteins were separated by PAGE. Measurement of unloaded cell shortening using video edge detection in single electrically stimulated myocytes was also used to assess the effects of AA and ET on myocyte contractility. Incubation with either PMA, AA, or ET resulted in similar increases in P-32(i) incorporation into troponin I (TnI) and myosin light chain 2 (MLC2), whichwas inhibited by preincubation with the protein kinase C antagonist calphostin C. In addition, the ability of these agonists to stimulate phosphorylation of TnI or MLC2 did not require extracellular Ca2+ or intact intracellular Ca2+ stores. The effects of AA and ET together on phosphorylation of TnI or MLC2 were not additive. These results show that AA and ET phosphorylate myofibrillar proteins in intact cardiac myocytes via a calphostin C-inhibitable Ca2+-independent pathway and thatAA, like ET, stimulates a positive inotropic effect in cardiac myocytes. Thus, phosphorylation of cardiac myofilaments by AA and/or ET, in addition to phosphorylation-dependent inhibition of distinct K+ channels, may represent an important signaling pathway by which AA and ET influence the inotropic state of the heart.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 22:04:50