Capel, I.D., Williams, D.C., Davey, R.W. and Patterson, M.A.. Amelioration of restraint stress by electrostimulation. IRCS Medical Science: Biochemistry, Environmental Biology and Medicine, Nervous System, Pharmacology, Psychology and Psychiatry. 7:634, 1979.
Device: 100 Hz, pulse width 0.22 mS, mean voltage of 9 to 11 V.
Two groups of 6 male Sprague-Dawley rats of body weight 250 +/- 20 g were housed 6 per cage in standard high density polypropylene cages on sawdust bedding. Each ear was pierced by insertion of a Michel suture clip. 24 hours after insertion of the ear clips the rats were placed in individual restraining cages. Electric current was passed from the CES device through the ear clip electrodes via alligator clips attached to the sutures. Sham treated animals were connected in the same way, but no electricity was passed. Both sets of animals remained in their restraining cages for 3 hours. Plasma cortisol levels were significantly lower (P<0.001) in the CES treated rats (70 +/-32 ng/ml) compared with the sham (162 +/- 22 ng/ml). There was no significant change in liver weight or microsomal protein in either CES or sham treated rats. Aryl hydrocarbon hydroxylase (P<0.001), nitroanisole demethylase (P<0.05) and uridine diphosphoglucuronic acid transferase (P<0.05) of the CES treated animals were significantly higher than those of the sham treated controls. Paradoxically, the activity of the mixed function oxidases was increased by CES despite the decreased cortisol levels. The authors concluded that further work is necessary to elucidate the mechanisms by which CES enhances hepatic enzyme activity.