Das experimentelle HIPA-Plasmozytom der Maus

Abstract

HIPA tumor is the denomination of an experimental plasmacytoma of mice. It can be transmitted by inoculation of cell-free extracts in syngenic or allogenic mice or by tumor cell transplant in syngenic mice. HIPA tumor was originally induced in the mesentery of BALB/c mice by intraperitoneal injection of spleen homogenate, obtained from a syngenic mouse, pretreated with incomplete Freund’s adjuvant. The original HIPA tumor was histologically an undifferentiated sarcoma. It underwent differentiation to plasmacytoma in the course of several transplant generations. This differentiation was characterized by loss of collagen fibers and appearance of annulate lamellae and dilatation of ergastoplasmic cysternae. HIPA tumor presented the following characteristics: (a) secretion of abnormal proteins in the course of the 3rd to 28th transplant generation; (b) appearance of a thrombocytopenía in the host after intraperitoneal inoculation of tumor cells; (c) formation of osteolytical and osteoplastic bone lesions after inoculation of tumor cells; (d) absence of splenic metastases regardless of the route of tumor inoculation. Oncogenic virus-like type C and A particles were found in the spleen of mineral oil-treated BALB/c mice and in HIPA tumor tissues of numerous transplant generations. After repeated attempts to isolate and enrich HIPA oncogenic virus by conventional methods, a double inoculation method was devised. It consisted of an initial intraperitoneal transplantation of HIPA tumor cells followed by intraperitoneal injection of HIPA cell-free tumor extracts. This procedure was repeated in several subsequent generations. Cell-free extracts of tumors which developed after double inoculation contained numerous virus-like type C particles. Such extracts induced plasmacytomas in syngenic and allogenic mice.