Study type: Medical/biological study (experimental study)

Protein oxidation under extremely low frequency electric field in guinea pigs. Effect of N-acetyl-L-cysteine treatment. med./bio.

Published in: Gen Physiol Biophys 2009; 28 (1): 47-55

Aim of study (acc. to author)

To study the effects of free radicals on proteins by means of detecting protein carbonyl content, advanced oxidation protein products and 3-nitrotyrosine in guinea pigs under the effect of 50 Hz electric fields.

Background/further details

Concurrent with the application of the electric field, the administration of N-acetyl-cysteine was also investigated in order to explain if it acts as antioxidant, reduce oxidative damage or as pro-oxidant in tissue medium. Hepatic hydroxyproline level was also examined to study protein synthesis.
A total of 40 male guinea pigs were randomly divided into four groups composed of 10 animals: 1) control group (injection of saline solution), 2) electric field exposure group (+ injection of saline solution 30 min before the daily exposure), 3) N-acetyl-cysteine administration + sham exposure group, 4) N-acetyl-cysteine administration (30 minutes before exposure) + electric field exposure group.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 8 hr/day on 7 days

General information

animals were treated in four groups: i) control group - sham exposure ii) E-field exposure iii) daily injection of 300 mg/kg NAC + sham exposure iv) daily injection of 300 mg/kg NAC + E-field exposure

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 8 hr/day on 7 days
Exposure setup
Exposure source
  • two 0.2 cm thick copper plates 80 cm x 80 cm
Setup 80 cm x 80 cm x 18 cm wooden cages with the copper plates mounted on the top and bottom of the cage
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 12 kV/m - measured and calculated - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No statistically significant changes occurred in protein carbonyl content, advanced oxidation protein products and 3-nitrotyrosine levels of the guinea pigs that were exposed to the electric field compared to the control group. However, liver hydroxyproline level was significantly diminished in the electric field exposure group compared to the control group.
These results may be caused by the fact that electric field exposure may affect the early formation of stable oxidized proteins, changing the direction of the reaction of oxidized proteins or Ieading to structural damage in protein synthesis although no statistically significant change was found in the levels of protein carbonyl content and advanced oxidation protein products.
Protein carbonyl content, advanced oxidation protein products and 3-nitrotyrosine levels changed significantly in the N-acetyl-cysteine-administrated groups (group 3 and 4).

Study character:

Study funded by

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