Anosmia and toxicity of topical intranasal zinc

Abstract

Intranasal application of ZnSO4 solutions has constituted a widely used method for the induction of a reversible loss of olfactory acuity in small laboratory animals. Three experiments are reported attempting to clarify the confounding issue of Zn toxicity. Experiment 1 demonstrated a significant growth lag in juvenile male rats following a series of intranasal ZnSO4 treatments. Experiment 2 compared intranasal and intragastric administration of isotonic ZnSO4 and saline solutions in mature males; only intranasally Zn-treated animals sustained a precipitous weight loss, presumably due to systemic absorption and consequent toxicity. Experiment 3 compared the effects of chronic and acute ZnSO4-induced anosmia on a variety of behaviors. The results are interpreted as supportive of a technique inducing reversible peripheral anosmia of several months’ duration with the unique advantage of permitting the dissipation of acute Zn toxicity prior to experimentation and avoiding common behavioral confounds. © 1977, Psychonomic Society, Inc.. All rights reserved.