Administration of 9 mg ketamine per 100 g b.wt. to rats leads to transient enhancement of immunoreactivity to monoclonal antibodies against two stress proteins, ubiquitin and human 70 kDa heat shock protein (HSP70), in the supranuclear region of supporting cells of the olfactory epithelium and in the Bowman's gland acinar cells in the subepithelial lamina propria. In the supporting cells the enhanced immunoreactivities are not caused by other drugs used in our surgical anesthetic/antibiotic regimen (xylazine, buprenorphine, and gentamicin), but in Bowman's glands they are. Results are discussed in terms of possible ketamine binding to phencyclidine receptors (either NMDA-associated or not) and possible direct stress-inducing interactions of ketamine or ketamine breakdown products with the inhalant detoxification or secretory systems in the reactive cells.