| Autor: |
Moura, Carlos Tiago Martins, Bezerra, Fernanda Carvalho, de Moraes, Isabelle Maciel, Magalhães, Pedro Jorge Caldas, Capaz, Francisco Ruy |
| Předmět: |
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| Zdroj: |
Clinical & Experimental Pharmacology & Physiology; Dec2005, Vol. 32 Issue 12, p1119-1123, 5p, 1 Chart, 3 Graphs |
| Abstrakt: |
1. Antigenic challenge often induces hyperreactivity in asthmatic airway, although the precise mechanism(s) underlying this increased responsiveness is not entirely known. 2. Tracheae obtained from ovalbumin (OVA)-sensitized saline- or OVA-challenged rats were placed in 10 mL bath chambers for isometric recording of 5-hydroxytryptamine (5-HT)-induced contractions. 3. 5-Hydroxytryptamine induced a stronger contraction compared with control in antigen-challenged trachea under normal or Ca2+-free conditions. 4. In tracheae pretreated with the L-type Ca2+ channel blocker nifedipine (10−6 mol/L) or the Ca2+-activated Cl– channel blocker niflumic acid (10−4 mol/L), this hyperresponsiveness was not developed in either normal or Ca2+-free medium. 5. The increased contractile response to 5-HT in allergic rat isolated trachea may be related to a greater ionic (Ca2+ and Cl–) channel involvement. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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