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Olfaction and Olfactory Epithelium in Mice Treated With Zinc Gluconate
Author(s) -
Slotnick Burton,
Sanguino Angelica,
Husband Scott,
Marquino Gregory,
Silberberg Alan
Publication year - 2007
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1097/mlg.0b013e318033006b
Subject(s) - olfactory epithelium , olfactory bulb , olfactory system , olfaction , odor , nasal administration , medicine , endocrinology , chemistry , biology , pharmacology , neuroscience , central nervous system
Objective : We assessed whether a nasal spray containing zinc gluconate (ZG) compromises the integrity of olfactory epithelium and olfactory function. Methods : Axonal transport of horseradish peroxidase from olfactory epithelium to the olfactory bulb was studied in 2‐ to 21‐day survival mice given intranasal injections of 2, 8, or 50 μL of ZG (approximately 4, 15, and 94 times the equivalent recommended human dose). Other similarly treated mice were tested using precision olfactometry to detect and discriminate odors. Results : Anatomic changes were graded as a function of dose and survival time. Two microliter injections had no discernable effect. While the 50 μL volume produced substantial deafferentation of input to the olfactory bulb in short‐survival cases. Nearly complete restitution of input occurred within 3 weeks. At each volume and survival time, zinc sulfate (ZS) had a greater effect. Behaviorally, 2 μL and 8 μL ZG‐treated mice and those given multiple injections of 2 μL ZG performed as well as controls, whereas those given 50 μL were hyposmic but not anosmic. ZS‐treated mice performed more poorly, and those injected with 50 μL were anosmic for the first 8 to 10 test days. Conclusions : A massive dose of a ZG nasal spray did cause a transient disruption of the olfactory epithelium and compromised olfaction. More moderate volumes, even those far in excess of a recommended dose, were largely without effect on odor detection and discrimination tasks. These outcomes fail to support the claims from recent clinical case reports that use of a ZG‐containing nasal spray can produce anosmia.