Respiratory and cardiovascular reflexes elicited by nasal instillation of capsaicin to anesthetized, spontaneously breathing dogs.
Cardiopulmonary reflexes elicited by capsaicin (CAPS) instilled into the nasal passages were determined in 6 anesthetized dogs breathing spontaneously. Nasal instillation of CAPS (10 microg/ml, 10 ml) induced: 1) apneic response characterized by an increase in expiration time; 2) bronchoconstrictor response characterized by an increase in lung resistance and a decrease in dynamic compliance; and 3) cardiovascular response characterized by a decrease in heart rate and an increase in arterial blood pressure. These reflex responses to CAPS were attenuated by pretreatment with a higher dose of CAPS (100 microg/ml, 10 ml), suggesting desensitization of CAPS-sensitive endings. These results suggest that marked cardiopulmonary reflexes are produced by nasal CAPS instillation, which may result, at least in part, from stimulation of nasal CAPS-sensitive sensory afferents.
Kanamaru
A
A
Department of Comparative Pathophysiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
Mutoh
T
T
Nishimura
R
R
Sasaki
N
N
Kuwahara
M
M
Tsubone
H
H
D000281:Administration, Intranasal; D000779:Anesthetics, Local / Q000008:administration & dosage; D000818:Animals; D001049:Apnea / Q000139:chemically induced / Q000662:veterinary; D001794:Blood Pressure / Q000187:drug effects; D016084:Bronchoconstriction / Q000187:drug effects; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D004285:Dogs / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D009296:Nasal Cavity / Q000294:innervation*; D012018:Reflex / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects*; D012129:Respiratory Function Tests / Q000662:veterinary
D000779:Anesthetics, Local; D008012:Lidocaine; D002211:Capsaicin