[Comparison between therapeutic effects of transcutaneous electrical nerve stimulation with the frequency of 2 Hz and 100 Hz on Chronic inflammatory pain in rats].

OBJECTIVE: To observe the effects of repeated transcutaneous nerve stimulation (TENS) with low frequency (2 Hz) and high frequency (100 Hz) on the chronic inflammatory pain.
METHODS: The complete Freund's adjuvant was used to make the monoadjuvant arthritis as a chronic inflammatory pain model. The model animals were divided into 3 groups, the 100 Hz TENS group, the 2 Hz TENS group and the control group. The percentage increase of body weight, circumference of ankle, score of flexion pain test and score of extension pain test were used to evaluate the therapeutic effect of TENS.
RESULTS: (1) Body weight increasing rate in the 100 Hz TENS group was markedly higher than that in the 2 Hz TENS group and the control group. (2) Circumference of rats' ankle in the 100 Hz TENS group was smaller than that in the 2 Hz TENS and the control group. (3) Repeated 100 Hz TENS showed more effective on pain relief than that of 2 Hz TENS.
CONCLUSION: TENS has therapeutic effects on chronic inflammatory pain in rats, and different frequencies yielded different results.