INHIBITORY EFFECTS OF ALPRAZOLAM ON THE ENHANCEMENT OF LUNG METASTASES INDUCED BY OPERATIVE STRESS IN RATS

Experiments were performed in order to evaluate the effects of alprazo lam (I mg/kg s.c.), a central benzodiazepine agonist anxiolytic, on th e development of lung metastases in rats subjected to laparotomy and i njected (i.v.) with 10(4) Walker 256 (W-256) carcinosarcoma cells. The number of metastatic nodules on the surface of the lungs, as well as the percentage-area of metastases in the frontal section through pulmo nary hilus were increased in rats subjected to sham-surgery or laparot omy. Treatment with alprazolam partially reversed those adverse effect s of surgery, but the difference was clearer when it was administered before surgery was performed. Survival periods were also assessed and alprazolam was found to decrease the lethality of rats exposed to surg ery. Pretreatment with Ro 15-1788, a central benzodiazepine antagonist , suppressed the inhibitory effects of alprazolam on tumor growth.