PMID: 9648958Jul 2, 1998Paper

Attenuation of isocapnic hyperpnoea-induced guinea-pig bronchoconstriction by chronic hypoxia

The European Respiratory Journal
Y L LaiL C Lai

Abstract

Chronic hypoxia has been shown to augment the production of antioxidants in rat lungs and to reduce airway hyperreactivity in patients with asthma. This study investigated indirectly whether this increase in antioxidants occurs in guinea-pig lungs and whether the increased antioxidants affect hyperpnoea-induced bronchoconstriction (HIB). Guinea-pigs were divided into four groups: control (n=8); chronic hypoxia (n=7); capsaicin pretreatment (n=7); and capsaicin pretreatment plus chronic hypoxia (n=8). Control animals were not treated. Animals in the hypoxia group were intermittently exposed to an ambient pressure of 380 mmHg for 7 days. A five day pretreatment of capsaicin was used to deplete tachykinins. In the last group, animals were pretreated with capsaicin, followed by a seven day hypoxic exposure. On the day of the study, airway function was examined in the anaesthetized and paralysed animal. Fifteen minutes of hyperpnoea caused marked decreases in the maximal expiratory flow rate at 15% vital capacity, forced expiratory volume in one second, and dynamic respiratory compliance, indicating HIB. This HIB and plasma substance P levels were significantly attenuated by chronic hypoxia, capsaicin pretreatment, and capsaicin pre...Continue Reading

Citations

Oct 17, 2003·The Journal of Physiology·Chau-Fong ChenMing-Shiou Wu
Jul 18, 2002·Pancreatology : Official Journal of the International Association of Pancreatology (IAP) ... [et Al.]·S P IpP S Leung
Mar 9, 2010·Experimental Lung Research·Patrícia Pennacchioni-AlvesCelso Ricardo Fernandes Carvalho

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