Quercetin Reverses the Enhanced Contractile Responses of Tracheal Smooth Muscle of Neonatal Rats Exposed to Hyperoxia

Abstract

Neonatal hyperoxia increases contraction and decreases the relaxation of airway smooth muscle (ASM), and the balance between these processes in airways is critical for normal flow of air. Thus, it is important to search for an effective treatment to prevent the airway hyperreactivity. Therefore, we tested the hypothesis that supplementation of quercetin will overcome the enchanced contractile responses of tracheal smooth muscle exposed to hyperoxia. Tracheal cylinders were obtained from Wistar rat pups (P12) exposed to hyperoxia (≥ 95% O2) or room air for seven days. These cylinders were used to study contractile responses of ASM evoked by methacholine (MCh, 10‐8 – 10‐4 M) in absence or presence of quercetin (100 μM). MCh induced dose‐dependent contractile responses of ASM. Hyperoxic exposure significantly increased the contractile responses of ASM towards MCh, as compared to those obtained from control animals exposed to room air, and these enhanced contractile responses in hyperoxic tissues were significantly attenuated in presence of quercetin. The results of this study revealed that quercetin reverses the enhanced contractile responses of airway smooth muscle induced by hyperoxic exposure and we speculate that the use of quercetin might be an effective therapeutic approach to prevent the airway hyperreactivity induced by hyperoxia.Support or Funding InformationSupported by MEST