Behavioural and immunological effects of the antihistamine terfenadine in olfactory bulbectomized rats

Examined the effects of chronic treatment with non-sedative histamine H-sub-1 receptor antagonist terfenadine on the behavioral and immunological parameters in the olfactory bulbectomized (OB) rat model of depression. OB Sprague-Dawley rats were injected with saline or terfenadine for 16 days after surgery. OB Ss showed a significant increase in ambulation and rearing scores in the open field apparatus. After terfenadine treatment, this hyperactivity was significantly attenuated. Neutrophils phagocytosis and lymphocyte proliferation were significantly suppressed in untreated OB Ss. Terfenadine markedly reversed the suppression of these immunological parameters in the treated OB Ss, but did not reverse the abnormalities in the differential white blood cell count caused by bulbectomy. These results suggest that terfenadine may have antidepressant properties and is effective in reversing some of behavioral and immune changes in this model of depression.