Objectives: Cholecystokinin, a satiety hormone, acts on cholecystokinin A receptor on vagal afferent neurons that project to the nucleus tractus solitarius, resulting in inhibition of feeding. Cholecystokinin is known to be released by electroacupuncture stimulation at certain body sites which elicits profound psychophysiological responses. Our previous study has revealed the involvement of cholecystokinin and cholecystokinin A receptor in the electroacupuncture stimulation-induced modulation of feeding. The aim of the present study was to examine whether electroacupuncture stimulation at the acupuncture point ST36 (Joksamni) activates the nucleus tractus solitarius neurons and whether such effect is mediated by cholecystokinin A receptor. Methods: Using an immunofluorescent analysis of Fos, a neuronal activation marker, we compared the Fos immunoreactivity of the nucleus tractus solitarius among three groups of Sprague-Dawley rats: (1) control (48 hour fasting z saline pre-treatment z no electroacupuncture stimulation); (2) SalEA (48 hour fasting z saline pre-treatment z ST36 electroacupuncture stimulation); (3) LorEA (48 hour fasting z pre-treatment of cholecystokinin A receptor antagonist, lorglumide z ST36 electroacupuncture stimulation). Results: ST36 electroacupuncture stimulation significantly reduced 30 minute food intake (p<0.05, SalEA versus control) and increased Fos expression in the nucleus tractus solitarius (p<0.01, SalEA versus control). The effects of electroacupuncture on food intake and Fos were blocked by a lorglumide pre-treatment (p>0.05, LorEA versus control). Discussion: Our finding suggests that ST36 electroacupuncture stimulation activates the nucleus tractus solitarius neurons via cholecystokinin A receptor signaling pathway, which may be the underlying central mechanism of electroacupuncture-induced satiety effect. [Neurol Res 2010; 32: 116-119] © 2010 W. S. Maney & Son Ltd.
Electroacupuncture; Fos; Lorglumide; Nucleus tractus solitarius; Satiety
EMTREE drug terms: cholecystokinin A receptor; lorglumide; protein fos; sodium chloride
EMTREE medical terms: animal experiment; animal tissue; article; controlled study; diet restriction; electroacupuncture; food intake; immunofluorescence test; immunoreactivity; male; nonhuman; protein expression; rat; signal transduction; solitary tract nucleus
MeSH: Animals; Eating; Electroacupuncture; Fasting; Fluorescent Antibody Technique; Hormone Antagonists; Male; Neurons; Proglumide; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Signal Transduction; Solitary Nucleus
Medline is the source for the MeSH terms of this document.
Chemicals and CAS Registry Numbers: lorglumide, 97964-56-2; sodium chloride, 7647-14-5;Hormone Antagonists; Proglumide, 6620-60-6; Proto-Oncogene Proteins c-fos; Receptor, Cholecystokinin A; lorglumide, 97964-56-2