title: Naltrexone pretreatment blocks microwave-induced changes in central cholinergic receptors.
abstract: Repeated exposure of rats to pulsed, circularly polarized microwaves (2,450-MHz, 2-microseconds pulses at 500 pps, power density 1 mW/cm2, at an averaged, whole-body SAR of 0.6 W/kg) induced biphasic changes in the concentration of muscarinic cholinergic receptors in the central nervous system. An increase in receptor concentration occurred in the hippocampus of rats subjected to ten 45-min sessions of microwave exposure, whereas a decrease in concentration was observed in the frontal cortex and hippocampus of rats exposed to ten 20-min sessions. These findings, which confirm earlier work in the authors' laboratory, were extended to include pretreatment of rats with the narcotic antagonist naltrexone (1 mg/kg, IP) before each session of exposure. The drug treatment blocked the microwave-induced changes in cholinergic receptors in the brain. These data further support the authors' hypothesis that endogenous opioids play a role in the effects of microwaves on central cholinergic systems.
authors.affiliation: Department of Pharmacology, University of Washington School of Medicine, Seattle 98195.
authors.forename: H
authors.initials: H
authors.lastname: Lai
authors.forename: M A
authors.initials: MA
authors.lastname: Carino
authors.forename: Y F
authors.initials: YF
authors.lastname: Wen
authors.forename: A
authors.initials: A
authors.lastname: Horita
authors.forename: A W
authors.initials: AW
authors.lastname: Guy
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000528:radiation effects*; D008297:Male; D008872:Microwaves; D009271:Naltrexone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000528:radiation effects*
chemical_list: D011976:Receptors, Muscarinic; D009271:Naltrexone