| 1. |
- Johansson, Andreas, et al.
(författare)
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The relative impact of chronic food restriction and acute food deprivation on plasma hormone levels and hypothalamic neuropeptide expression
- 2008
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 29:9, s. 1588-1595
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding of the central regulation of food intake and body weight has increased tremendously through implication of a high number of neuropeptides. However, lack of all-embracing studies have made comparison difficult in the past. The objective of this study was to demonstrate the relative importance of the different neuropeptides in terms of involvement in appetite regulatory mechanisms. We quantified expression levels of 21 hypothalamic neuropeptides and circulating levels of leptin, insulin, corticosterone, adrenocorticotropic hormone, ghrelin and adiponectin in rats after acute food deprivation and chronic food restriction using validated quantitative real-time PCR and hormone measurements. Body weight, insulin and leptin were reduced whereas corticosterone was increased by both acute food deprivation and chronic food restriction. Our results confirmed the relative importance in body weight homeostasis of neuropeptide Y and proopiomelanocortin, which were increased and decreased as predicted. The expression of other neuropeptides previously attributed central roles in body weight homeostasis, e.g. melanin-concentrating hormone and orexin, appeared to be less affected by the treatments. Moreover, the expression of dynorphin, galanin-like peptide and neuropeptide B was dramatically reduced after both treatments. This suggests that the latter neuropeptides--although previously known to be involved in body weight homeostasis--may be of unexpected importance in states of negative energy balance.
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| 2. |
- Pickering, Chris, et al.
(författare)
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The role of hypothalamic peptide gene expression in alcohol self-administration behavior.
- 2007
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 28:12, s. 2361-2371
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Tidskriftsartikel (refereegranskat)abstract
- Self-administration of ethanol and food share many common features and Richter hypothesized that an increase in ethanol consumption would decrease feeding to balance the excess calories contained in the ethanol. Previously, we have shown that individual alcohol consumption correlates with neurotransmitter gene expression, especially in the prefrontal cortex. To test the hypothesis of Richter, we measured hypothalamic gene expression of receptors or neuropeptides of known relevance for the regulation of food intake using qPCR and correlated this to individual ethanol consumption in Wistar rats. For validation, gene expression was first correlated with body weight. We found a correlation of dynorphin, somatostatin, melanocortin-4 receptor and serotonin 5-HT2C with body weight and trends to correlation for CART, thus confirming the established role of the hypothalamus in the regulation of weight. For ethanol consumption, correlations were found for CRH receptors I and 2 and vasopressin while strong trends were observed for galanin receptor 1, orexin receptor 1, MCH and adrenoceptor alpha(1B). Therefore, alcohol consumption does seem to involve several hypothalamic systems which also mediate feeding responses and suggests that the hypothalamus, together with the prefrontal cortex, may determine the 'stopping point' of an individual.
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