Effects of intranasal ZnSO4 irrigation on olfactory and trigeminal cues

• Published in: Physiology & behavior Vol. 55; no. 4; p. 699
• Main Authors: Hansen, L F, Hammer, M, Petersen, S H, Nielsen, G D
• Format: Journal Article
• Language: English
• Published: United States 01-04-1994
• Subjects: 1-Propanol - pharmacology; Animals; Appetitive Behavior - drug effects; Appetitive Behavior - physiology; Cues; Dose-Response Relationship, Drug; Male; Mice; Olfactory Mucosa - innervation; Olfactory Nerve - drug effects; Olfactory Nerve - physiology; Pulmonary Ventilation - drug effects; Pulmonary Ventilation - physiology; Reaction Time - drug effects; Reaction Time - physiology; Smell - drug effects; Smell - physiology; Sulfates - pharmacology; Therapeutic Irrigation; Trigeminal Nerve - drug effects; Trigeminal Nerve - physiology; Zinc Compounds - pharmacology; Zinc Sulfate
• ISSN: 0031-9384
• DOI: 10.1016/0031-9384(94)90047-7

Intranasal irrigation with ZnSO4 solutions is used for experimental induction of anosmia. It is, however, unknown whether the trigeminal nerve is affected by the treatment. One day after irrigation (concentrations investigated were between 0.05-1%) the ability of food finding, an olfactory cue, was decreased in a concentration-dependent manner. The trigeminal effect was investigated from a reflexively induced decrease in respiratory rate due to n-propanol exposure. No impairment occurred at 1% ZnSO4. Anosmia was also seen 2-3 h after an irrigation with solutions of 0.05-1% ZnSO4. At the same time, 0.2 and 1% solutions in themselves decreased the respiratory rate due to reflexes from the upper and lower respiratory tract. A conspicuous systemic effect can be ruled out as the Zn++ antidote, CaNa2EDTA, had no effect on the decrease. A direct activation of the trigeminal nerve due to a reaction with a thiol group may explain the effect from the upper airways.