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Selective blockades of agonist‐induced reflex and afferent responses of vagal lung C‐fibers by perivagal antagonist treatment in rats
Author(s) -
Lin YuJung,
Ruan Ting,
Kou Yu Ru
Publication year - 2013
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.27.1_supplement.930.22
Subject(s) - capsazepine , ppads , reflex , capsaicin , agonist , trpv1 , pharmacology , chemistry , tropisetron , receptor , stimulation , antagonist , endocrinology , medicine , transient receptor potential channel
It has been known that several types of pharmacological receptors are expressed on the terminals of vagal lung C‐fibers (VLCFs). These receptors play crucial roles in triggering airway reflexes and in the development of airway hypersensitivity. This study was carried out to use perivagal treatment with antagonists (PAT) targeting the TRPV1, P2X and 5‐HT 3 receptors to block reflex and afferent responses of VLCF to intravenous injections of agonists in anesthetized rats. Capsaicin, α,β‐methylene‐ATP, and phenylbiguanide were used as the agonists, and capsazepine, iso ‐PPADS, and tropisetron were used as the antagonists of TRPV1, P2X, and 5‐HT 3 receptors, respectively. Perivagal capsazepine treatment prevented both VLCF‐mediated reflex apneic and afferent firing response to intravenous injections of capsaicin but not to α,β‐methylene‐ATP and phenylbiguanide. Similar patterns of the selective blockade by PAT to corresponding agonists were also found in iso ‐PPADS and tropisetron. Our results indicate that PAT selectively abolished the stimulatory action of corresponding agonists on the VLCF terminals, which suggest that PAT has the possibility to become a novel intervention for studying the role of pharmacological receptors in the functioning of VLCFs (NSC 98–2628‐B‐040–011‐MY3 and NSC 101–2320‐B‐010–042‐MY3).