Local microwave hyperthermia (43 degrees C) and stimulation of the macrophage and T-lymphocyte systems in treatment of Guerin epithelioma in rats.

Abstract

Rats bearing Guerin epithelioma were exposed to 3 or 6 sessions of local microwave hyperthermia (LMwH) (2450 MHz, tumor temperature 43° C, time of exposition 45 min) on the 3rd or 5th week after implantation of tumor cells. In some of the animals LMwH was combined with the administration of immunopotentiating (IP) substances—purified Streptolysin S (SLS) (1 mg/kg b.w.) or Corynebacterium parvum (CP) (1 mg/kg b.w., intratumorally)-injected 3 times weekly on the 4th and 6th weeks after implantation of tumor cells. All the animals were immunized with bovine serum albumine (BSA) 2 and 3 weeks after tumor implantation. Size of tumors was measured each 4 days and the growth curves were analysed. Eight weeks after implantation all the animals were killed and the following tests were performed: weight of tumors, BSA antibodies titre (passive hemagglutination test using BSA-glutaraldehyde coupled sheep red blood cells), 3H-leucine and 3H-uridine incorporation to phytohemagglutinin (PHA)-stimulated spleen lymphocytes and to mixed tumor cell-lymphocyte cultures, cytotoxicity of isolated spleen lymphocytes and peritoneal macrophages to 51Cr-labeled primary cultures of Guerin tumor cells, lysozyme (muramidase) activity in blood serum.