The 1.3 isoform of Na+Ca2+ exchanger expressed in guinea pig tracheal smooth muscle is less sensitive to KB-R7943
J. physiol. biochem
; 66(2): 117-125, jun. 2010.
Artigo
em Inglês
| IBECS
| ID: ibc-122835
Biblioteca responsável:
ES1.1
Localização: BNCS
RESUMEN
No disponible
ABSTRACT
The sodiumcalcium exchanger (NCX) plays a major role in the regulation of cytosolic Ca2+ in muscle cells. In this work, we performed force experiments to explore the role of NCX during contraction and relaxation of Cch-stimulated guinea pig tracheal smooth muscle strips. This tissue showed low sensitivity to NCX inhibitor KB-R7943 (IC50, 57 ± 2 µM), although a complete relaxation was obtained by NCX inhibition at 100 µM. Interestingly, relaxation after washing the agonist was prolonged in the absence of external Na+, whereas washing without Na+ and in the presence of KB-R7943 resembled control conditions with physiological solution. Altogether, this suggests the reversal of NCX to a Ca2+ influx mode by the manipulation on the Na+ gradient, which can be inhibited by KB-R7943. In order to understand the low sensitivity to KB-R7943, we studied the molecular aspects of the NCX expressed in this tissue and found that the isoform of NCX expressed is 1.3, similar to that described in human tracheal smooth muscle. Sequencing revealed that amino acid 19 in exon B is phenylalanine, whereas in its human counterpart is leucine, and that the first amino acid after exon D is aspartate instead of glutamate in humans. Results herein presented are discussed in term of their possible functional implications in the exchanger activity and thus in airway physiology (AU)
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Coleções:
Bases de dados nacionais
/
Espanha
Base de dados:
IBECS
Assunto principal:
Fenilalanina
/
Aspartato Quinase
/
Ácido Glutâmico
/
Trocador de Sódio e Cálcio
/
Leucina
Tipo de estudo:
Estudo diagnóstico
Limite:
Animais
/
Humanos
Idioma:
Inglês
Revista:
J. physiol. biochem
Ano de publicação:
2010
Tipo de documento:
Artigo
Instituição/País de afiliação:
Universidad Autónoma de San Luis Potosí/México
/
University of Western Ontario/Canada