Limits...
Sensitivity to the satiating effects of exendin 4 is decreased in obesity-prone Osborne-Mendel rats compared to obesity-resistant S5B/Pl rats.

Primeaux SD, Barnes MJ, Braymer HD, Bray GA - Int J Obes (Lond) (2010)

Bottom Line: GLP-1 is produced in the small intestine and is released in response to a meal.Experiment 3 examined the effects of exendin-4 (GLP-1 receptor agonist) administration on the intake of a high-fat or a low-fat diet in OM and S5B rats.The intake of low-fat diet, compared to the intake of high-fat diet, was more sensitive to the effects of exendin-4 in these strains.

View Article: PubMed Central - PubMed

Affiliation: Dietary Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA. Stefany.Primeaux@pbrc.edu

ABSTRACT

Background: Osborne-Mendel (OM) rats are prone to obesity when fed a high-fat diet, whereas S5B/Pl (S5B) rats are resistant to diet-induced obesity when fed the same diet. OM rats have a decreased satiation response to fatty acids infused in the gastrointestinal tract, compared to S5B rats. One possible explanation is that OM rats are less sensitive to the satiating hormone, glucagon-like peptide 1 (GLP-1). GLP-1 is produced in the small intestine and is released in response to a meal. The current experiments examined the role of GLP-1 in OM and S5B rats.

Methods: Experiment 1 examined preproglucagon mRNA expression in the ileum of OM and S5B rats fed a high-fat (55% kcal) or low-fat (10% kcal) diet. Experiment 2 investigated the effects of a 2 h high-fat meal after a 24 h fast in OM and S5B rats on circulating GLP-1 (active) levels. Experiment 3 examined the effects of exendin-4 (GLP-1 receptor agonist) administration on the intake of a high-fat or a low-fat diet in OM and S5B rats.

Results: Preproglucagon mRNA levels were increased in the ileum of OM rats compared to S5B rats and were increased by high-fat diet in OM and S5B rats. OM and S5B rats exhibited a similar meal-initiated increase in circulating GLP-1 (active) levels. Exendin-4 dose dependently decreased food intake to a greater extent in S5B rats compared to OM rats. The intake of low-fat diet, compared to the intake of high-fat diet, was more sensitive to the effects of exendin-4 in these strains.

Conclusions: These results suggest that though OM and S5B rats have similar preproglucagon mRNA expression in the ileum and circulating GLP-1 levels, OM rats are less sensitive to the satiating effects of GLP-1. Therefore, dysregulation of the GLP-1 system may be a mechanism through which OM rats overeat and gain weight.

Show MeSH

Related in: MedlinePlus

Daily low fat and high fat food intake was measured for 14 days. OM rats ate more high fat food (HF) than low fat food (LF) throughout the 14 days. S5B rats ate more high fat food (HF) than low fat food (LF) on most days. OM rats consumed more high fat diet than S5B rats from Days 2–13. Data is expressed in kilocalories (kcal) and shown as mean ± SEM. * OM high fat diet vs. OM low fat diet; # S5B high fat diet vs. S5B low fat diet; (p<.05).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2910155&req=5

Figure 1: Daily low fat and high fat food intake was measured for 14 days. OM rats ate more high fat food (HF) than low fat food (LF) throughout the 14 days. S5B rats ate more high fat food (HF) than low fat food (LF) on most days. OM rats consumed more high fat diet than S5B rats from Days 2–13. Data is expressed in kilocalories (kcal) and shown as mean ± SEM. * OM high fat diet vs. OM low fat diet; # S5B high fat diet vs. S5B low fat diet; (p<.05).

Mentions: Food intake was measured daily for 2 weeks prior to sacrifice. A strain × day × diet interaction (F(13,442)=2.04, p<.02, Figure 1) and strain × diet interaction (F(1,34)=24.79,p<.0001) were detected. Post-hoc analyses revealed that OM rats consumed significantly more high fat diet (kcal) than low fat diet (kcal) throughout the experiment (p<.05). S5B rats consumed significantly more high fat diet than low fat diet on most days (days 1, 2, 3, 4, 7, 9, 10, 11, 12, and 14; p<.05). OM rats consumed more high fat diet than S5B rats throughout the experiment, except for Days 1 and 14, while OM rats consumed more low fat diet than S5B rats on Days 1, 10 and 12 (p<.05). Body weight was measured weekly prior to sacrifice.


Sensitivity to the satiating effects of exendin 4 is decreased in obesity-prone Osborne-Mendel rats compared to obesity-resistant S5B/Pl rats.

Primeaux SD, Barnes MJ, Braymer HD, Bray GA - Int J Obes (Lond) (2010)

Daily low fat and high fat food intake was measured for 14 days. OM rats ate more high fat food (HF) than low fat food (LF) throughout the 14 days. S5B rats ate more high fat food (HF) than low fat food (LF) on most days. OM rats consumed more high fat diet than S5B rats from Days 2–13. Data is expressed in kilocalories (kcal) and shown as mean ± SEM. * OM high fat diet vs. OM low fat diet; # S5B high fat diet vs. S5B low fat diet; (p<.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2910155&req=5

Figure 1: Daily low fat and high fat food intake was measured for 14 days. OM rats ate more high fat food (HF) than low fat food (LF) throughout the 14 days. S5B rats ate more high fat food (HF) than low fat food (LF) on most days. OM rats consumed more high fat diet than S5B rats from Days 2–13. Data is expressed in kilocalories (kcal) and shown as mean ± SEM. * OM high fat diet vs. OM low fat diet; # S5B high fat diet vs. S5B low fat diet; (p<.05).
Mentions: Food intake was measured daily for 2 weeks prior to sacrifice. A strain × day × diet interaction (F(13,442)=2.04, p<.02, Figure 1) and strain × diet interaction (F(1,34)=24.79,p<.0001) were detected. Post-hoc analyses revealed that OM rats consumed significantly more high fat diet (kcal) than low fat diet (kcal) throughout the experiment (p<.05). S5B rats consumed significantly more high fat diet than low fat diet on most days (days 1, 2, 3, 4, 7, 9, 10, 11, 12, and 14; p<.05). OM rats consumed more high fat diet than S5B rats throughout the experiment, except for Days 1 and 14, while OM rats consumed more low fat diet than S5B rats on Days 1, 10 and 12 (p<.05). Body weight was measured weekly prior to sacrifice.

Bottom Line: GLP-1 is produced in the small intestine and is released in response to a meal.Experiment 3 examined the effects of exendin-4 (GLP-1 receptor agonist) administration on the intake of a high-fat or a low-fat diet in OM and S5B rats.The intake of low-fat diet, compared to the intake of high-fat diet, was more sensitive to the effects of exendin-4 in these strains.

View Article: PubMed Central - PubMed

Affiliation: Dietary Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA. Stefany.Primeaux@pbrc.edu

ABSTRACT

Background: Osborne-Mendel (OM) rats are prone to obesity when fed a high-fat diet, whereas S5B/Pl (S5B) rats are resistant to diet-induced obesity when fed the same diet. OM rats have a decreased satiation response to fatty acids infused in the gastrointestinal tract, compared to S5B rats. One possible explanation is that OM rats are less sensitive to the satiating hormone, glucagon-like peptide 1 (GLP-1). GLP-1 is produced in the small intestine and is released in response to a meal. The current experiments examined the role of GLP-1 in OM and S5B rats.

Methods: Experiment 1 examined preproglucagon mRNA expression in the ileum of OM and S5B rats fed a high-fat (55% kcal) or low-fat (10% kcal) diet. Experiment 2 investigated the effects of a 2 h high-fat meal after a 24 h fast in OM and S5B rats on circulating GLP-1 (active) levels. Experiment 3 examined the effects of exendin-4 (GLP-1 receptor agonist) administration on the intake of a high-fat or a low-fat diet in OM and S5B rats.

Results: Preproglucagon mRNA levels were increased in the ileum of OM rats compared to S5B rats and were increased by high-fat diet in OM and S5B rats. OM and S5B rats exhibited a similar meal-initiated increase in circulating GLP-1 (active) levels. Exendin-4 dose dependently decreased food intake to a greater extent in S5B rats compared to OM rats. The intake of low-fat diet, compared to the intake of high-fat diet, was more sensitive to the effects of exendin-4 in these strains.

Conclusions: These results suggest that though OM and S5B rats have similar preproglucagon mRNA expression in the ileum and circulating GLP-1 levels, OM rats are less sensitive to the satiating effects of GLP-1. Therefore, dysregulation of the GLP-1 system may be a mechanism through which OM rats overeat and gain weight.

Show MeSH
Related in: MedlinePlus