Immunohistochemical changes in orexigenic and anorexigenic neuropeptides in the rat hypothalamus after capsaicin administration.
Capsaicin has effects on the adiposity by increasing energy and lipid metabolism, and decreases appetite and fat intake. In the present study, we investigated changes in food intake and body weight after capsaicin treatment. We also observed changes in orexigenic and anorexigenic neuropeptides-agouti-related peptide (AgRP), alpha-melanocyte-stimulating hormone (alpha-MSH), adrenocorticotropic hormone (ACTH) and orexin-immunoreactivities in the rat hypothalamus after capsaicin administration. Only one day after capsaicin treatment, the mean food intake was significantly decreased. There was no significant difference in the mean body weight between vehicle- and capsaicin-treated groups. In addition, after capsaicin treatment, numbers of AgRP- and orexin-immunoreactive ((+)) cells were significantly decreased in the arcuate nucleus (ARC) and lateral hypothalamic area, respectively. In contrast, the number of alpha-MSH(+) and ACTH(+) cells in the ARC of the capsaicin-treated rats was higher than in the vehicle-treated rats. These results indicate that capsaicin reduces food intake, not body weight, transiently, and decreases AgRP and orexin immunoreactivities, whereas it increases alpha-MSH and ACTH immunoreactivities in rat hypothalamic nuclei.
Lee
Choong Hyun
CH
Department of Anatomy, and Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon 200-702, South Korea.
Choi
Jung Hoon
JH
Hwang
In Koo
IK
Yoo
Ki-Yeon
KY
Li
Hua
H
Park
Ok Kyu
OK
Yan
Bingchun
B
Shin
Hyung-Cheul
HC
Won
Moo-Ho
MH
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D054369:Agouti-Related Protein / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002211:Capsaicin / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D051381:Rats; D000521:alpha-MSH / Q000378:metabolism
C515197:AGRP protein, rat; D054369:Agouti-Related Protein; D009479:Neuropeptides; D000521:alpha-MSH; D000324:Adrenocorticotropic Hormone; D002211:Capsaicin