Naltrexone pretreatment blocks microwave-induced changes in central cholinergic receptors.
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.
Lai
H
H
Department of Pharmacology, University of Washington School of Medicine, Seattle 98195.
Carino
M A
MA
Wen
Y F
YF
Horita
A
A
Guy
A W
AW
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*
D011976:Receptors, Muscarinic; D009271:Naltrexone