Symptomatic therapy of influenza rhinitis in ferrets by topical application of compounds

A variety of compounds including pharmacologically active agents have been tested for topical efficacy against various manifestations of disease in ferrets resulting from infection with influenza. All compounds so examined which are used to treat rhinitis in human beings were able to suppress the development of nasal congestion in this system. Other compounds were also effective. With the exception of caprochlorone, an antiviral, all compounds appeared to possess pharmacologic action, since one dose administered at a time when the disease was well established diminished nasal congestion. Other characteristics of compound action were also examined, including dose response, duration of action, and effect on normal nasal mucosa. A consideration of the mediators of inflammation in ferret influenza rhinitis from structure-activity relationships suggests that histamine may play an important role in this process, but serotonin does not. When the compounds were tested against other manifestations of disease, all failed to suppress fever, to increase erythrocyte sedimentation, to increase blood neutrophil-lymphocyte ratios, and to enhance nasal extrusion of systemically injected dye. However, several inhibited leukocyte increase in nasal wash. Activity with these compounds was expressed when the initial application was delayed until 24 hours after infection but not after one treatment given one hour before nasal wash. The activity can be attributed at least in part to inhibition of viral replication in turbinates.