Paola Algara-Suárez, Catalina Romero-Méndez, Tom Chrones, Sergio Sánchez-Armass, Ulises Meza, Stephen M Sims, Ricardo Espinosa-Tanguma
Airway smooth muscle (ASM) contracts partly due to an increase in cytosolic Ca(2+). In this work, we found that the contraction caused by histamine depends on external Na(+), possibly involving nonselective cationic channels (NSCC) and the Na(+)/Ca(2+) exchanger (NCX). We performed various protocols using isometric force measurement of guinea pig tracheal rings stimulated by histamine. We observed that force reached 53 +/- 1% of control during external Na(+) substitution by N-methyl-D-glucamine(+), whereas substitution by Li(+) led to no significant change (91 +/- 1%)...
July 2007: American Journal of Physiology. Lung Cellular and Molecular Physiology