Involvement of specific orexigenic neuropeptides in sweetener-induced overconsumption in rats

Autor: Yuichi Furudono, Chiho Ando, Takashi Yamamoto, Chizuko Yamamoto, Motoi Kobashi
Rok vydání: 2006
Předmět:
Male
medicine.medical_specialty
Melanin-concentrating hormone
Peptide Hormones
Neuropeptide
Dynorphin
Hyperphagia
Dynorphins
Behavioral Neuroscience
chemistry.chemical_compound
Internal medicine
Orexigenic
mental disorders
medicine
Animals
Agouti-Related Protein
Neuropeptide Y
RNA
Messenger
Rats
Wistar
Saccharin
Injections
Intraventricular
Melanins
Orexins
Hypothalamic Hormones
Gastric emptying
Appetite Regulation
digestive
oral
and skin physiology
Neuropeptides
Intracellular Signaling Peptides and Proteins
Feeding Behavior
Ghrelin
Orexin
Rats
Pituitary Hormones
Endocrinology
nervous system
chemistry
Sweetening Agents
Taste
Intercellular Signaling Peptides and Proteins
Gastrointestinal Motility
psychological phenomena and processes
hormones
hormone substitutes
and hormone antagonists
medicine.drug
Zdroj: Behavioural brain research. 175(2)
ISSN: 0166-4328
Popis: Palatability is one of the factors that regulates food and fluid intake and contributes to overconsumption in turn contributing to obesity. To elucidate the brain mechanisms of the palatability-induced ingestion, we explored the roles of six hypothalamic orexigenic neuropeptides, orexin, melanin-concentrating hormone (MCH), neuropeptide Y (NPY), agouti-related protein (AgRP), ghrelin and dynorphin, in the intake of a palatable solution, saccharin. Of the six peptides, intracerebroventricular (i.c.v.) administrations of orexin, MCH and NPY increased the intake of saccharin. Drinking of saccharin in turn elevated the mRNA levels of orexin and NPY, but not MCH. Pre-treatments of naloxone, an opioid antagonist, blocked the orexigenic effects of orexin and NPY. Specific gastric motor responses induced by central orexin-A and NPY are well known, however, MCH did not induce such responses. The i.c.v. administration of orexin-A facilitated gastric emptying. These results suggest that the overconsumption promoted by sweet and palatable tastes is attributed to the activation of orexigenic neuropeptides, such as orexin and NPY, and a downstream opioid system together with enhanced digestive functions.
Databáze: OpenAIRE
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