Acute effects of pulsed microwaves and 3-nitropropionic acid on neuronal ultrastructure in the rat caudate-putamen med./bio.

To study possible combined effects of 3-nitropropionic acid induced chemical hypoxia and microwave exposure in the rat caudate-putamen.

3-nitropropionic acid irreversibly inhibits succinate dehydrogenase in the brain. This reduces production of adenosine triphosphate and the resulting interruption in energy metabolism can trigger oxidative stress, nitric oxide production and NMDA receptor activation consequently lead to neuronal cell death.
Rats were given doses of 10 mg/kg 3-nitropropionic acid and 1.5 h after were exposed to microwave irradiation.

• animal
• rat/Sprague-Dawley
• whole body

Tissue samples showed no injury with light microscope methods. Assessment of ultrastructure of randomly selected neurons from the same samples did reveal differences. Administration of 3-nitropropionic acid significantly increased endoplasmic reticulum intracisternal width, endoplasmic reticulum area density, and nuclear envelope thickness. Microwave irradiation at 6 W/kg alone also significantly increased these measures. Exposure of 3-nitropropionic acid treated rats at 6 W/kg significantly increased effects of 3-nitropropionic acid on ultrastructure. Although irradiation at 0.6 W/kg alone did not affect ultrastructure measures, exposure of 3-nitropropionic acid treated rats at 0.6 W/kg reduced the effects of 3-nitropropionic acid.
The authors concluded that 3-nitropropionic acid changed neuronal ultrastructure and that the microwave exposures used here altered neuronal ultrastructure in ways that depended on microwave SAR and neuron metabolic status. The apparent cancellation of 3-nitropropionic acid induced changes by exposure to pulsed microwaves at 0.6 W/kg indicated the possibility that such irradiation can protect against the effects of mitochondrial toxins on the nervous system.