title: Effects of microwave exposure on the hamster immune system. II. Peritoneal macrophage function.
abstract: Acute exposure to hamsters to microwave energy (2.45 GHz; 25 mW/cm2 for 60 min) resulted in activation of peritoneal macrophages that were significantly more viricidal to vaccinia virus as compared to sham-exposed or normal (minimum-handling) controls. Macrophages from microwave-exposed hamsters became activated as early as 6 h after exposure and remained activated for up to 12 days. The activation of macrophages by microwave exposure paralleled the macrophage activation after vaccinia virus immunization. Activated macrophages from vaccinia-immunized hamsters did not differ in their viricidal activity when the hamsters were microwave- or sham-exposed. Exposure for 60 min at 15 mW/cm2 did not activate the macrophages while 40 mW/cm2 exposure was harmful to some hamsters. Average maximum core temperatures in the exposed (25 mW/cm2) and sham groups were 40.5 degrees C (+/- 0.35 SD) and 38.4 degrees C (+/- 0.5 SD), respectively. In vitro heating of macrophages to 40.5 degrees C was not as effective as in vivo microwave exposure in activating macrophages to the viricidal state. Macrophages from normal, sham-exposed, and microwave-exposed hamsters were not morphologically different, and they all phagocytosed India ink particles. Moreover, immune macrophage cytotoxicity for virus-infected or noninfected target cells was not suppressed in the microwave-irradiated group (25 mW/cm2, 1 h) as compared to sham-exposed controls, indicating that peritoneal macrophages were not functionally suppressed or injured by microwave hyperthermia.
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions / Q000528:radiation effects; D001202:Ascitic Fluid / Q000166:cytology; D002460:Cell Line; D006224:Cricetinae; D003602:Cytotoxicity, Immunologic / Q000528:radiation effects; D008262:Macrophage Activation / Q000528:radiation effects; D008264:Macrophages / Q000276:immunology / Q000528:radiation effects*; D008647:Mesocricetus; D008872:Microwaves; D010587:Phagocytosis / Q000528:radiation effects; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014616:Vaccinia virus / Q000276:immunology