title: Increased serum enzyme activity in microwave-exposed rats.
abstract: Heat stable serum enzymes were studied in rats exposed to microwaves (2.45 GHz, 120 Hz amplitude modulated) 24 hr after a single 4-hr exposure or immediately after 3 and 10 exposures to 0.1 to 55 mW/cm2. In addition, stable colonic temperature at 41.5 degrees C for 30 min was maintained by microwave exposure in a group of five rats under barbiturate anesthesia. Alkaline phosphatase and lactic dehydrogenase did not increase as a result of microwave exposure. Increased serum glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) were noted in the 41.5 degrees C group 24 hr after exposure. A threshold body temperature for acute cellular injury after microwave exposure was demonstrated. The acute cellular injury could be in the liver. These mild elevations in the serum enzyme levels (mean +/- SE, GOT = 167 +/- 40 U/liter: GPT = 74 +/- 26 U/liter) indicated that the injuries were not accompanied by any significant sequelae in the rat. From this threshold and colonic temperature (41.5 degrees C for 30 min) in barbiturate-anesthetized, microwave-exposed rats, we derived a tentative threshold for the whole-body average absorption rate at 14 W/kg (70 mW/cm2 at 2.45 GHz for adult rats) for 4 hr. This tentative threshold is subject to changes by duration of exposure and by compounding variables influencing maintenance of body temperature.
mesh_terms: D000410:Alanine Transaminase / Q000097:blood / Q000528:radiation effects*; D000469:Alkaline Phosphatase / Q000097:blood / Q000528:radiation effects*; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood / Q000528:radiation effects*; D001831:Body Temperature; D003106:Colon; D004307:Dose-Response Relationship, Radiation; D007770:L-Lactate Dehydrogenase / Q000097:blood / Q000528:radiation effects*; D008297:Male; D008872:Microwaves / Q000009:adverse effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
chemical_list: D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase