Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs
Research article published in British journal of pharmacology (1999)
Abstract
Antioxidants attenuate noncholinergic airway constriction. To further investigate the relationship between tachykinin-mediated airway constriction and oxygen radicals, we explored citric acid-induced bronchial constriction in 48 young Hartley strain guinea-pigs, divided into six groups: control; citric acid; hexa(sulphobutyl)fullerenes + citric acid; hexa(sulphobutyl)fullerenes + phosphoramidon + citric acid; dimethylthiourea (DMTU) + citric acid; and DMTU + phosphoramidon + citric acid. Hexa(sulphobutyl)fullerenes and DMTU are scavengers of oxygen radicals while phosphoramidon is an inhibitor of the major degradation enzyme for tachykinins. Animals were anaesthetized, paralyzed, and artificially ventilated. Each animal was given 50 breaths of 4 ml saline or citric acid aerosol. We measured dynamic respiratory compliance (Crs), forced expiratory volume in 0.1 (FEV0.1), and maximal expiratory flow at 30% total lung capacity (Vmax30) to evaluate the degree of airway constriction. Citric acid, but not saline, aerosol inhalation caused marked decreases in Crs, FEV0.1 and Vmax30, indicating marked airway constriction. This constriction was significantly attenuated by either hexa(sulphobutyl)fullerenes or by DMTU. In addition, phosphoramidon significantly reversed the attenuating action of hexa(sulphobutyl)fullerenes, but not that of DMTU. Citric acid aerosol inhalation caused increases in both lucigenin- and t-butyl hydroperoxide-initiated chemiluminescence counts, indicating citric acid-induced increase in oxygen radicals and decrease in antioxidants in bronchoalveolar lavage fluid. These alterations were significantly suppressed by either hexa(sulphobutyl)fullerenes or DMTU. An elastase inhibitor eglin-c also significantly attenuated citric acid-induced airway constriction, indicating the contributing role of elastase in this type of constriction. We conclude that both oxygen radicals and elastase play an important role in tachykinin-mediated, citric acid-induced airway constriction.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Antioxidants attenuate noncholinergic airway constriction.
Por qué esto importa para la hirudoterapia
Este estudio en animales investigó los papeles de los radicales de oxígeno y de la elastasa en la constricción de las vías aéreas inducida por ácido cítrico en 48 cobayos, empleando captadores de radicales e inhibidores enzimáticos. Entre los agentes probados, la eglin-c —descrita en el resumen solo como «un inhibidor de elastasa»— atenuó significativamente la constricción de las vías aéreas inducida por ácido cítrico, lo que respalda la conclusión de que la elastasa desempeña un papel contribuyente en la broncoconstricción mediada por taquicininas. Este hallazgo es de relevancia indirecta para el dominio de la ASH solo si la eglin-c se considera en el contexto de moléculas bioactivas derivadas de sanguijuela, aunque el propio resumen no aporta un origen en sanguijuelas para la eglin-c. El estudio no es una investigación de hirudoterapia; la eglin-c se emplea como compuesto herramienta de investigación más que como intervención terapéutica, los experimentos involucran cobayos y el foco es la fisiología de las vías aéreas. El resumen no establece ninguna conexión explícita con la sanguijuela.
Citación
Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs
Lai YL et al. · British journal of pharmacology, 1999
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026