Differential calcium movements induced by agonists in guinea pig tracheal muscle.
Eur J Pharmacol
; 133(1): 111-7, 1987 Jan 06.
Article
em En
| MEDLINE
| ID: mdl-3556387
ABSTRACT
The effects of high potassium, carbachol and histamine on tension responses and 45Ca fluxes in tracheal smooth muscle were examined. Calcium depletion or nitrendipine (10(-8) M) inhibited potassium-induced contractile responses more than those obtained with either histamine or carbachol, whereas Sr2+ inhibited mainly responses to histamine or carbachol. The Ca2+ entry facilitator, CGP 28392 (3 X 10(-6) M), potentiated contractions induced only by potassium. Uptake of 45Ca in guinea pig tracheal muscle can be separated into high and low affinity components. The 45Ca efflux rate from tracheal muscle into a La3+-substituted solution was over four-fold higher than in other smooth muscles. Potassium, carbachol and histamine induced sustained increases in 45Ca efflux into solutions containing 1.5 mM Ca2+; only transient increases in 45Ca efflux with carbachol and histamine were obtained after Ca2+ depletion. These agonists elicit contractile responses in tracheal muscle by selectively mobilizing different cellular and extracellular Ca2+ components.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Traqueia
/
Cálcio
Limite:
Animals
Idioma:
En
Ano de publicação:
1987
Tipo de documento:
Article