TY  - JOUR
AU  - Long Jing-wen
AU  - Yang Xu-dong
AU  - Cao Lei
AU  - Lu She-min
AU  - Cao Yong-xiao
PY  - 2016
TI  - Alteration of airway responsiveness mediated by receptors in ovalbumin-induced asthmatic E3 rats
JF  - Acta Pharmacologica Sinica; Vol 30, No 7 (July 2009): Acta Pharmacologica Sinica
Y2  - 2016
KW  - 
N2  -  Aim:  Airway hyperresponsiveness is a constant feature of asthma. The aim of the present study was to investigate airway hyperreactivity mediated by contractile and dilative receptors in an ovalbumin (OVA)-induced model of rat asthma.   Methods:  Asthmatic E3 rats were prepared by intraperitoneal injection with OVA/aluminum hydroxide and then challenged with intranasal instillation of OVA-PBS two weeks later. The myograph method was used to measure the responses of constriction and dilatation in the trachea, main bronchi and lobar bronchi.   Results:  In asthmatic E3 rats, β 2  adrenoceptor-mediated relaxation of airway smooth muscle pre-contracted with 5-HT was inhibited, and there were no obvious difference in relaxation compared with normal E3 rats. Contraction of lobar bronchi mediated by 5-HT and sarafotoxin 6c was more potent than in the trachea or main bronchi. Airway contractions mediated by the endothelin (ET) A  receptor, ETB receptor and M 3  muscarinic receptor were augmented, and the augmented contraction was most obvious in lobar bronchi. The order of efficacy of contraction for lobar bronchi induced by agonists was ET-1, sarafotoxin 6c>ACh>5-HT. OX8 (an antibody against CD8 +  T cells) strongly shifted and OX35 (an antibody against CD4 +  T cells) modestly shifted isoprenaline-induced concentration-relaxation curves in a nonparallel fashion to the left with an increased Rmax in asthmatic rats and sarafotoxin 6c-induced concentration-contractile curves to the right with a decreased  E  max .   Conclusion:  The inhibition of airway relaxation and the augmentation of contraction mediated by receptors contribute to airway hyperresponsiveness and involve CD8 +  and CD4 +  T cells.
UR  - http://www.chinaphar.com/article/view/5106