[Ca2+]i changes in guinea pig tracheal smooth muscle cells in culture: effects of Na+ and ouabain.
The objective of this work was to confirm that the contractile effects of ouabain and Na(+)-free solutions in guinea pig tracheal rings are associated with increments in the cytosolic free Ca2+ concentration ([Ca2+]i) in cultured tracheal smooth muscle (TSM) cells. Cultured cells were alpha-actin positive. Histamine (50 microM) and Na(+)-free solution elicited a transient increase in [Ca2+]i, while the responses to thapsigargin (1 microM) and ouabain (1 mM) were long lasting. However, carbachol (10, 200, and 500 mM) and high K(+)-solution produced no effect on [Ca2+]i, suggesting that cultured guinea pig TSM cells display a phenotype change but maintain some of the tracheal rings physiological properties. The transient rise in [Ca2+]i in response to the absence of extracellular Na+ and the effect of ouabain may indicate the participation of the Na(+)/Ca2+ exchanger (NCX) in the regulation of [Ca2+]i.
Espinosa-Tanguma
R
R
Departamento de Fisiología y Farmacología, Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, Av. V. Carranza 2405, San Luis Potosí, 78210, S.L.P., México.
Guevara
C
C
González
J
J
Ortega
F
F
Ramírez-Zacarías
J L
JL
Hernández
A E
AE
Mandeville
P
P
Sánchez-Armass
S
S
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002217:Carbachol / Q000494:pharmacology; D002412:Cations; D002478:Cells, Cultured; D016257:Fura-2 / Q000031:analogs & derivatives*; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology*; D012964:Sodium / Q000494:pharmacology*; D019831:Sodium-Calcium Exchanger / Q000378:metabolism; D019284:Thapsigargin / Q000494:pharmacology; D013997:Time Factors; D014132:Trachea / Q000187:drug effects* / Q000378:metabolism
D002412:Cations; D019831:Sodium-Calcium Exchanger; C098106:fura-PE3; D010042:Ouabain; D019284:Thapsigargin; D006632:Histamine; D002217:Carbachol; D012964:Sodium; D000252:Calcium-Transporting ATPases; D002118:Calcium; D016257:Fura-2