Multiple sources of endogenous opioid peptide involved in the hypoglycemic response to 15 Hz electroacupuncture at the Zhongwan acupoint in rats.
A decrease in plasma glucose levels was observed in rats which received electroacupuncture (EA) stimulation at the Zhongwan acupoint. In the present study, the role of the adrenal gland in this hypoglycemic response to EA at high frequency (15 Hz) was investigated on adrenalectomized (ADX) normal rats. There was a sharper decrease in plasma glucose by EA stimulation in the fasting ADX group than in the fasting sham-operated group. Naloxone blocked this hypoglycemic response to EA stimulation in rats which received ADX. Stimulation of EA failed to elicit an increase in plasma beta-endorphin and insulin levels in ADX rats. Similar results were observed in sham and ADX mice. EA stimulation of ADX mice can reduce plasma glucose levels. Furthermore, naloxone abolished the hypoglycemic response to EA stimulation in mice. Such a hypoglycemic response to EA stimulation was also observed in micro-opioid receptor knockout mice (MOR-KOM). Mediation by another opioid peptide should also be considered in future experiments. We conclude that multiple sources of endogenous opioid peptide participated in the lowering of plasma glucose in rats induced by EA stimulation at higher frequency (15 Hz) at the Zhongwan acupoint. Increase in beta-endorphin levels from the adrenal gland enhances the secretion of insulin, there by reducing plasma glucose levels, and is partially involved in this EA stimulation.
Lin
Jaung-Geng
JG
Taipei Chinese Medical Association, Taipei City, Taiwan, ROC.
Chen
Wang-Chuan
WC
Hsieh
Ching-Liang
CL
Tsai
Chin-Chuan
CC
Cheng
Yu-Wen
YW
Cheng
Juei-Tang
JT
Chang
Shih-Liang
SL
D015669:Acupuncture Points; D015670:Acupuncture Therapy; D000311:Adrenal Glands / Q000502:physiology; D000315:Adrenalectomy; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D005215:Fasting; D007328:Insulin / Q000097:blood; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018847:Opioid Peptides / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000235:genetics; D001615:beta-Endorphin / Q000097:blood
D001786:Blood Glucose; D007328:Insulin; D018847:Opioid Peptides; D017450:Receptors, Opioid, mu; D001615:beta-Endorphin