Elimination of microwave effects on the vitality of nerves after blockage of active transport
We have previously reported that exposure to microwave fields (a specific absorption rate of 10 W/kg at 2.45-GHz continuous wave) would consistently lower the survival time of isolated frog sciatic nerves stimulated at high repetition rates (50 pulse pairs per second, ppps). The time course of the loss of excitability of the exposed nerve (as compared to its unexposed contralateral mate) is reminiscent of that seen when the active transport of sodium (Na) and potassium (K) is blocked by certain agents--such as the cardiac glycoside ouabain. To assess the role that these microwaves may have in interfering with or counteracting active transport, we performed a series of experiments in which the active Na-K pump was substantially blocked by ouabain prior to microwave exposure. The paired nerves were soaked for 5 min in a high concentration (10(-3) g/liter) of ouabain to achieve the fastest and most complete blockage of the Na-K pump prior to stimulation at 50 ppps. The ''rundown time course'' was, as expected, accelerated in all ouabain-treated nerves, but the microwave-exposed nerves showed no additional shortening of survival time. The experiments were repeated at a slower stimulation rate (5 ppps) so that the survival time of the nerves more closely approximated that of nerves not treated with ouabain (1 to 2 h versus 30 min or less for ouabain-treated nerves stimulated at 50 ppps). Results of these lower stimulation rates also showed that there was no significant difference in the survival time of ouabain-treated exposed and control nerves. These results lend support to the view that the relative loss of excitability in microwave-exposed nerves is related to an interference with or counteraction of the Na-K pump.
- Research Organization:
- National Institute of Environmental Health Sciences, Research Triangle Park, NC
- OSTI ID:
- 6926601
- Journal Information:
- Radiat. Res.; (United States), Vol. 3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Pulse microwave effects on nerve vitality
Electrophysiologic deficits in peripheral nerve as a discriminator of early hexacarbon neurotoxicity. [Rats]
Related Subjects
MICROWAVE RADIATION
BIOLOGICAL EFFECTS
POTASSIUM
MEMBRANE TRANSPORT
SCIATIC NERVE
SURVIVAL TIME
SODIUM
FROGS
IN VITRO
OUABAIN
ALKALI METALS
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
DRUGS
ELECTROMAGNETIC RADIATION
ELEMENTS
GLYCOSIDES
METALS
NERVES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
RADIATIONS
STROPHANTHINS
VERTEBRATES
560400* - Other Environmental Pollutant Effects