Effects of vagal perineural capsaicin treatment on vagal efferent and airway neurogenic responses in anesthetized rats.
The acute effect of vagal perineural capsaicin treatment (VPCT) on parasympathetic bradycardia and tracheal neurogenic protein extravasation was examined. In nine anesthetized male Wistar rats the effect of VPCT on the bradycardia induced by electrical stimulation of the vagus was examined. In 24 anesthetized male Wistar rats the effect of VPCT on the tracheal protein extravasation induced by the inhalation of capsaicin aerosols was also studied. VPCT did not alter the bradycardia induced by vagal stimulation or the tracheal protein extravasation induced by the inhalation of capsaicin aerosol. The results of these studies further demonstrate the selectivity of perineural capsaicin treatment on vagal sensory nonmyelinated fibers in the rat and indicate that it is a useful tool for examining the role of sensory vagal C-fibers in pulmonary and cardiovascular reflexes and in isolating C-fiber-mediated reflex responses from those mediated by the release of neuropeptides.
Schelegle
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Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis 95616, USA. esschelegle@ucdavis.edu
Chen
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Loh
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D000200:Action Potentials / Q000187:drug effects; D000280:Administration, Inhalation; D000336:Aerosols; D000758:Anesthesia; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000294:innervation / Q000378:metabolism; D002199:Capillary Permeability / Q000187:drug effects; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D004558:Electric Stimulation; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology; D009476:Neurons, Efferent / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D012137:Respiratory System / Q000187:drug effects* / Q000294:innervation*; D014132:Trachea / Q000187:drug effects / Q000294:innervation / Q000378:metabolism; D014630:Vagus Nerve / Q000166:cytology / Q000187:drug effects*
D000336:Aerosols; D002211:Capsaicin