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High‐Frequency Electrical Stimulation (HES) of Vagus Nerves Reduces Airway Resistance (R L ) in Response to Methacholine (MCh) in Anesthetized Guinea Pigs
Author(s) -
Xu Fadi,
Zhuang Jianguo,
Bailet Daniel,
Curtis Robert,
Zhang Cancan
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1062.2
Subject(s) - bronchoconstriction , tachyphylaxis , medicine , methacholine , vagus nerve , stimulation , ovalbumin , anesthesia , cholinergic , airway resistance , reflex , vagotomy , guinea pig , hypertonic saline , vagus nerve stimulation , saline , plethysmograph , endocrinology , airway , lung , immunology , respiratory disease , immune system
Asthmatic patients are characterized by cholinergic‐mediated airway hyperreactivity and bronchoconstriction. Tachyphylaxis and safety‐related side effects of the drugs used to treat asthma are clinical challenges. Because vagotomy blunts the R L response to MCh and HES blocks nerve conduction, we hypothesized that HES of the cervical vagus nerve would reduce the R L responses to MCh, especially in ovalbumin (Ova)‐sensitized guinea pigs, an established animal model of asthma. Both saline (Sal)‐ and Ova‐treated animals were anesthetized, paralyzed, and ventilated. R L and its responses to 10 s of low frequency electrical stimulation (LES, 50 Hz) and HES (≥1 KHz, 0.5 V; 0.2‐ms pulse duration) were recorded before and after MCh (100 μg/ml/min for 2 min) inhalation. Only LES significantly increased R L in both groups of animals before MCh. After MCh, the R L was increased 2.5‐fold higher in the Ova‐ than Sal‐treated animals and LES still enhanced R L , but HES suppressed the R L response more greatly in the Ova‐ (49%) than the Sal‐treated animals (35%). These evoked R L responses completely followed the electrical stimulation in an on‐and‐off manner with little effect on cardiovascular activity. Our data suggest that HES is a potentially useful approach in alleviating asthmatic bronchoconstriction.