6533b82efe1ef96bd1293ed9
RESEARCH PRODUCT
Effect of serotonin and calcium in normal and sensitized guinea pig isolated trachea
Esteban J. MorcilloL. CompteLuisa BertoA. De DiegoJulio CortijoMiguel Perpiñásubject
Hypersensitivity ImmediateMaleSerotoninmedicine.medical_specialtyContraction (grammar)ATPaseGuinea Pigschemistry.chemical_elementIn Vitro TechniquesCalciumOuabainGuinea pigInternal medicinemedicineExtracellularAnimalsPharmacology (medical)Enzyme InhibitorsOuabain5-HT receptorPharmacologybiologyTracheaEndocrinologychemistrybiology.proteinCalciumSerotoninSodium-Potassium-Exchanging ATPaseMuscle Contractionmedicine.drugdescription
Tracheal strips from normal and actively sensitized guinea pigs were studied to determine the responses to serotonin (5-hydroxytryptamine, 5-HT ; 1 nM - 0.1 mM) and ouabain (0.1 μM - 0.1 mM), and the effects of increasing the extracellular calcium (Ca o ) concentration on tonic contractions elicited by 5-HT. Sensitized trachea exhibited an increased responsiveness and sensitivity to 5-HT and ouabain. Increases in Ca o to achieve final concentrations of 5, 10 and 20 mM caused concentration-related relaxations of normal and sensitized tissues contracted to a similar plateau level with 5-HT. Inhibition of the Na + /K + -ATPase by ouabain (10 μM) reversed the effects of Ca o from relaxation to contraction in normal and sensitized tissues contracted with 5HT. Sensitized preparations showed reduced relaxations in response to Ca o (10-20 mM), and sensitized, ouabain-treated, trachea showed augmented contractions to Ca o (10-20 mM) when compared to normal tissues. These results demonstrate a decreased membrane-stabilizing effect of Ca o in sensitized trachea and the implication of the Na + /K + -ATPase in the regulation of membrane stability by Ca o , suggesting a possible relevance to those mechanisms underlying airway hyperreactivity.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1996-01-02 |