Antitumor activity of an extract neurotropin isolated from the inflamed skin of rabbits inoculated with vaccinia virus

: The antitumor activity of extracts (Neurotropin (NSP)) isolated from the inflamed skin of rabbits inoculated was studied in syngeneic mice-tumor system, C57BL/6-with mammary adenocarcinoma 755. NSP at a dose of 2 mg/kg of body weight was administrated for seven days. Intravenous administration of NSP was more effective than intraperitoneal and subcutaneous administration. NSP exhibited antitumor activity against primary inoculated tumor growths with a cell dose of less than 1 x 10(5) viable cells. Antitumor activity was observed when NSP administration was started one day after tumor inoculation. NSP also enhanced antitumor activity against secondary tumor growths inoculated after excision of the primary tumor. The antitumor activity of Neurotropin seemed to be exerted through a host-mediated tumor immunity.