Corticosterone mediates electroacupuncture-produced anti-edema in a rat model of inflammation

Abstract

BackgroundElectroacupuncture (EA) has been reported to produce anti-edema and anti-hyperalgesia effects on inflammatory disease. However, the mechanisms are not clear. The present study investigated the biochemical mechanisms of EA anti-inflammation in a rat model.MethodsThree experiments were conducted on male Sprague-Dawley rats (n = 7–8/per group). Inflammation was induced by injecting complete Freund's adjuvant (CFA) subcutaneously into the plantar surface of one hind paw. Experiment 1 measured plasma corticosterone (CORT) levels to see if EA regulates CORT secretion. Experiment 2 studied the effects of the adrenal gland on the therapeutic actions of EA using adrenalectomy (ADX) rats. Experiment 3 determined whether a prototypical glucocorticoid receptor antagonist, RU486, affects EA anti-edema. EA treatment, 10 Hz at 3 mA and 0.1 ms pulse width, was given twice, for 20 min each, once immediately after CFA administration and again 2 h post-CFA. Plasma CORT levels, paw thickness, indicative of the intensity of inflammation, and paw withdrawal latency (PWL) were measured 2 h and 5 h after the CFA injection.ResultsEA significantly increased plasma corticosterone levels 2 h (5 folds) and 5 h (10 folds) after CFA administration compared to sham EA control, but EA alone in naive rats and CFA alone did not induce significant increases in corticosterone. Adrenalectomy blocked EA-produced anti-edema, but not EA anti-hyperalgesia. RU486 (15 μl, 15 μg/μl), a prototypical glucocorticoid receptor antagonist, also prevented EA anti-edema.ConclusionThe data demonstrate that EA activates the adrenals to increase plasma corticosterone levels and suppress edema and suggest that EA effects differ in healthy subjects and in those with pathologies.

Mechanisms of Acupuncture–Electroacupuncture on Persistent Pain

“…The modality activated the hypothalamus-pituitary-adrenal axis to significantly increase plasma corticosterone levels in a CFA-inflammatory pain rat model 21,22 and significantly downregulated carrageenan-induced expression of COX-1, COX-2 mRNA, and their proteins. 23 It is known that the endocannabinoids anandamide and 2-arachidonoyl glycerol are metabolized by fatty acid amide hydrolase, monoacylglycerol lipase, and COX-2.…”

Application of acupuncture in the treatment of venous insufficiency and varicose veins

“…Acupuncture provides a significant improvement in the treatment of venous ulcers. [5,6] According to the traditional Chinese medicine, edema travelling from the knee toward the lower limb indicates spleen and kidney Yang deficiency with the accumulation and retention of damp and mucus, thereby, leading to edema. [7] Using the acupuncture technique, meridians of the spleen and kidney are the location for edema resolution.…”

Mediators, Receptors, and Signalling Pathways in the Anti-Inflammatory and Antihyperalgesic Effects of Acupuncture

“…Inflammatory oedema has been significantly reduced by acupuncture in rodent and murine models of induced hind paw inflammation [ 2 , 3 ]. This antioedema effect is mediated via the HPA axis as various disruptions of the HPA axis obliterate or significantly attenuate the effect [ 2 , 3 ].…”