Introduction of a high-energy diet acutely up-regulates hypothalamic cocaine and amphetamine-regulated transcript, Mc4R and brown adipose tissue uncoupling protein-1 gene expression in male Sprague-Dawley rats

Z A Archer, D V Rayner, Jackie Duncan, Lynn Thomson, Julian Mercer

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Obesity is an escalating problem in Western societies. Susceptibility to weight gain within an obesogenic environment is variable. It remains unclear how the range of weight gain responses are generated. It is possible that an individual's immediate and/or sustained appetite for apparently palatable foods, or metabolic adaptations to a new diet could be important. The present study therefore examined the short- to medium-term effects of a high-energy (HE) diet on bodyweight, food intake, and energy balance-related signalling systems. Sprague-Dawley rats were fed either chow or an HE diet for 12 h, 24 h, 48 h or 14 days. Blood hormones and metabolites were assayed, and expression of uncoupling protein-1 (UCP-1) and hypothalamic energy-balance related genes were determined by Northern blotting or in situ hybridisation, respectively. Short-term exposure (12 h, 24 h, 48 h) to the HE diet had no effect on grams of food consumed, but caloric intake was increased. Exposure to HE diet for 14 days (medium term) established a bodyweight differential of 7.7 g, and animals exhibited a transient increase in caloric intake of 5 days duration. Terminal levels of leptin, insulin, glucose and non-esterified fatty acids (NEFAs) were all increased in HE-fed animals. UCP-1 mRNA was elevated in interscapular brown adipose tissue from HE-fed rats only at 12 h. Cocaine and amphetamine-regulated transcript (CART) and Mc4R gene expression in the hypothalamus were increased after 12 h and 24 h on an HE diet, respectively. The rats appear to passively over-consume calories as a result of consuming a similar weight of a more energy dense food. This evokes physiological responses, which adjust caloric intake over several days. Circulating NEFA and insulin concentrations, UCP-1, Mc4R and CART gene expression are increased as an immediate consequence of consuming HE diet, and may be involved in countering hypercaloric intake. Circulating leptin is increased in the HE-fed animals after 48 h, reflecting their increasing adiposity.
Original languageEnglish
Pages (from-to)10-17
Number of pages8
JournalJournal of Neuroendocrinology
Volume17
Issue number1
DOIs
Publication statusPublished - 1 Jan 2005

Fingerprint

Amphetamine
Cocaine
Sprague Dawley Rats
Up-Regulation
Diet
Gene Expression
Energy Intake
Leptin
Food
Weight Gain
Fatty Acids
Insulin
Brown Adipose Tissue
Adiposity
Appetite
Uncoupling Protein 1
Northern Blotting
Hypothalamus
In Situ Hybridization
Obesity

Keywords

  • animal feed
  • animals
  • blood glucose
  • body weight
  • carrier proteins
  • energy intake
  • energy metabolism
  • nonesterified fatty acids
  • gene expression
  • hypothalamus
  • Insulin
  • ion channels
  • leptin
  • male
  • membrane proteins
  • mitochondrial proteins
  • nerve tissue proteins
  • rats
  • Sprague-Dawley rats
  • type 4 melanocortin receptor
  • up-regulation

Cite this

@article{2ce9a5da67f64d81818ccdfef0b21844,
title = "Introduction of a high-energy diet acutely up-regulates hypothalamic cocaine and amphetamine-regulated transcript, Mc4R and brown adipose tissue uncoupling protein-1 gene expression in male Sprague-Dawley rats",
abstract = "Obesity is an escalating problem in Western societies. Susceptibility to weight gain within an obesogenic environment is variable. It remains unclear how the range of weight gain responses are generated. It is possible that an individual's immediate and/or sustained appetite for apparently palatable foods, or metabolic adaptations to a new diet could be important. The present study therefore examined the short- to medium-term effects of a high-energy (HE) diet on bodyweight, food intake, and energy balance-related signalling systems. Sprague-Dawley rats were fed either chow or an HE diet for 12 h, 24 h, 48 h or 14 days. Blood hormones and metabolites were assayed, and expression of uncoupling protein-1 (UCP-1) and hypothalamic energy-balance related genes were determined by Northern blotting or in situ hybridisation, respectively. Short-term exposure (12 h, 24 h, 48 h) to the HE diet had no effect on grams of food consumed, but caloric intake was increased. Exposure to HE diet for 14 days (medium term) established a bodyweight differential of 7.7 g, and animals exhibited a transient increase in caloric intake of 5 days duration. Terminal levels of leptin, insulin, glucose and non-esterified fatty acids (NEFAs) were all increased in HE-fed animals. UCP-1 mRNA was elevated in interscapular brown adipose tissue from HE-fed rats only at 12 h. Cocaine and amphetamine-regulated transcript (CART) and Mc4R gene expression in the hypothalamus were increased after 12 h and 24 h on an HE diet, respectively. The rats appear to passively over-consume calories as a result of consuming a similar weight of a more energy dense food. This evokes physiological responses, which adjust caloric intake over several days. Circulating NEFA and insulin concentrations, UCP-1, Mc4R and CART gene expression are increased as an immediate consequence of consuming HE diet, and may be involved in countering hypercaloric intake. Circulating leptin is increased in the HE-fed animals after 48 h, reflecting their increasing adiposity.",
keywords = "animal feed, animals, blood glucose, body weight, carrier proteins, energy intake, energy metabolism, nonesterified fatty acids, gene expression, hypothalamus, Insulin, ion channels, leptin, male, membrane proteins, mitochondrial proteins, nerve tissue proteins, rats, Sprague-Dawley rats, type 4 melanocortin receptor , up-regulation",
author = "Archer, {Z A} and Rayner, {D V} and Jackie Duncan and Lynn Thomson and Julian Mercer",
year = "2005",
month = "1",
day = "1",
doi = "10.1111/j.1365-2826.2005.01269.x",
language = "English",
volume = "17",
pages = "10--17",
journal = "Journal of Neuroendocrinology",
issn = "0953-8194",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Introduction of a high-energy diet acutely up-regulates hypothalamic cocaine and amphetamine-regulated transcript, Mc4R and brown adipose tissue uncoupling protein-1 gene expression in male Sprague-Dawley rats

AU - Archer, Z A

AU - Rayner, D V

AU - Duncan, Jackie

AU - Thomson, Lynn

AU - Mercer, Julian

PY - 2005/1/1

Y1 - 2005/1/1

N2 - Obesity is an escalating problem in Western societies. Susceptibility to weight gain within an obesogenic environment is variable. It remains unclear how the range of weight gain responses are generated. It is possible that an individual's immediate and/or sustained appetite for apparently palatable foods, or metabolic adaptations to a new diet could be important. The present study therefore examined the short- to medium-term effects of a high-energy (HE) diet on bodyweight, food intake, and energy balance-related signalling systems. Sprague-Dawley rats were fed either chow or an HE diet for 12 h, 24 h, 48 h or 14 days. Blood hormones and metabolites were assayed, and expression of uncoupling protein-1 (UCP-1) and hypothalamic energy-balance related genes were determined by Northern blotting or in situ hybridisation, respectively. Short-term exposure (12 h, 24 h, 48 h) to the HE diet had no effect on grams of food consumed, but caloric intake was increased. Exposure to HE diet for 14 days (medium term) established a bodyweight differential of 7.7 g, and animals exhibited a transient increase in caloric intake of 5 days duration. Terminal levels of leptin, insulin, glucose and non-esterified fatty acids (NEFAs) were all increased in HE-fed animals. UCP-1 mRNA was elevated in interscapular brown adipose tissue from HE-fed rats only at 12 h. Cocaine and amphetamine-regulated transcript (CART) and Mc4R gene expression in the hypothalamus were increased after 12 h and 24 h on an HE diet, respectively. The rats appear to passively over-consume calories as a result of consuming a similar weight of a more energy dense food. This evokes physiological responses, which adjust caloric intake over several days. Circulating NEFA and insulin concentrations, UCP-1, Mc4R and CART gene expression are increased as an immediate consequence of consuming HE diet, and may be involved in countering hypercaloric intake. Circulating leptin is increased in the HE-fed animals after 48 h, reflecting their increasing adiposity.

AB - Obesity is an escalating problem in Western societies. Susceptibility to weight gain within an obesogenic environment is variable. It remains unclear how the range of weight gain responses are generated. It is possible that an individual's immediate and/or sustained appetite for apparently palatable foods, or metabolic adaptations to a new diet could be important. The present study therefore examined the short- to medium-term effects of a high-energy (HE) diet on bodyweight, food intake, and energy balance-related signalling systems. Sprague-Dawley rats were fed either chow or an HE diet for 12 h, 24 h, 48 h or 14 days. Blood hormones and metabolites were assayed, and expression of uncoupling protein-1 (UCP-1) and hypothalamic energy-balance related genes were determined by Northern blotting or in situ hybridisation, respectively. Short-term exposure (12 h, 24 h, 48 h) to the HE diet had no effect on grams of food consumed, but caloric intake was increased. Exposure to HE diet for 14 days (medium term) established a bodyweight differential of 7.7 g, and animals exhibited a transient increase in caloric intake of 5 days duration. Terminal levels of leptin, insulin, glucose and non-esterified fatty acids (NEFAs) were all increased in HE-fed animals. UCP-1 mRNA was elevated in interscapular brown adipose tissue from HE-fed rats only at 12 h. Cocaine and amphetamine-regulated transcript (CART) and Mc4R gene expression in the hypothalamus were increased after 12 h and 24 h on an HE diet, respectively. The rats appear to passively over-consume calories as a result of consuming a similar weight of a more energy dense food. This evokes physiological responses, which adjust caloric intake over several days. Circulating NEFA and insulin concentrations, UCP-1, Mc4R and CART gene expression are increased as an immediate consequence of consuming HE diet, and may be involved in countering hypercaloric intake. Circulating leptin is increased in the HE-fed animals after 48 h, reflecting their increasing adiposity.

KW - animal feed

KW - animals

KW - blood glucose

KW - body weight

KW - carrier proteins

KW - energy intake

KW - energy metabolism

KW - nonesterified fatty acids

KW - gene expression

KW - hypothalamus

KW - Insulin

KW - ion channels

KW - leptin

KW - male

KW - membrane proteins

KW - mitochondrial proteins

KW - nerve tissue proteins

KW - rats

KW - Sprague-Dawley rats

KW - type 4 melanocortin receptor

KW - up-regulation

U2 - 10.1111/j.1365-2826.2005.01269.x

DO - 10.1111/j.1365-2826.2005.01269.x

M3 - Article

VL - 17

SP - 10

EP - 17

JO - Journal of Neuroendocrinology

JF - Journal of Neuroendocrinology

SN - 0953-8194

IS - 1

ER -