Sensory irritation effects of n-propanol and ethylbenzene after pretreatment with capsaicin or indomethacin.
Irritation of upper respiratory tract (sensory irritation) due to two model solvents, ethylbenzene and propanol, were investigated from their reflex-induced decrease in respiratory rate in mice. Intranasal application of capsaicin decreased the sensory irritation response of both solvents, indicating that at least part of the sensory irritation effect must occur as a result of activation of capsaicin sensitive afferent nerves. The vehicle used for the application of capsaicin in itself decreased the respiratory rate strongly, either caused by effects on the upper respiratory tract or on the lungs. This demonstrates the need for a formulation of a pharmacologically inactive vehicle for nasal application of lipophilic substances. Pretreatment with indomethacin had no influence on sensory irritation of any of the solvents. This suggests that sensory irritation is caused by a direct interaction between receptors on the trigeminal nerves and the vapours rather than being an indirect effect of tissue damage giving rise to metabolites from the cyclooxygenase pathway.
Hansen
L F
LF
National Institute of Occupational Health, Copenhagen, Denmark.
Nielsen
G D
GD
D000433:1-Propanol / Q000633:toxicity*; D000818:Animals; D001555:Benzene Derivatives / Q000633:toxicity*; D002211:Capsaicin / Q000494:pharmacology*; D007213:Indomethacin / Q000494:pharmacology*; D007509:Irritants; D008297:Male; D051379:Mice; D009297:Nasal Mucosa / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D012119:Respiration / Q000187:drug effects* / Q000502:physiology; D012137:Respiratory System / Q000294:innervation*; D011984:Sensory Receptor Cells / Q000187:drug effects*; D014276:Trigeminal Nerve / Q000502:physiology
D001555:Benzene Derivatives; D007509:Irritants; D000433:1-Propanol; C004912:ethylbenzene; D002211:Capsaicin; D007213:Indomethacin