A transgenic dwarf rat model as a tool for the study of calorie restriction and aging

Yamaza, Haruyoshi; Komatsu, Toshimitsu; Chiba, Takuya; Toyama, Hiroaki; To, Kazuo; Higami, Yoshikazu; Shimokawa, Isao

doi:10.1016/j.exger.2003.11.001

Cited by 28 publications

(14 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The food intake and body weight in Tg-AL rats were similar to those in W-CR rats (Shimokawa et al, 2003). W-CR and Tg-AL rats also had normal or slightly improved glucose tolerance without a significant surge in the serum insulin concentration after glucose loading (Yamaza et al, 2004). Plasma adiponectin was increased in W-CR and Tg-AL rats, while plasma leptin was decreased (Yamaza et al, 2007).…”

Section: Introductionmentioning

confidence: 59%

“…In our previous study using the same experimental setting, we demonstrated that blood glucose levels significantly increased 15 min after glucose injection, but returned to an almost basal level more quickly in CR rats (Yamaza et al, 2004). Another study (Wetter et al, 1999) has also demonstrated that glucose injected intravenously was slightly but more quickly cleared from the circulation with lower levels of insulin in CR rats, while glucose uptake by some tissues was increased.…”

Section: Discussionmentioning

confidence: 96%

“…These results indicate sensitization of insulin action in the skeletal muscle by CR and GH suppression. Indeed, our previous study demonstrated an increase in whole body insulin sensitivity in W-CR and Tg-AL rats using insulin tolerance tests (Yamaza H et al, 2004). Because skeletal muscle is a major insulin-dependent organ, the enhanced whole body insulin sensitivity in CR and Tg rats could be mostly due to the increased insulin sensitivity in skeletal muscles by CR or GH suppression.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Calorie restriction minimizes activation of insulin signaling in response to glucose: Potential involvement of the growth hormone-insulin-like growth factor 1 axis

Hayashi

Yamaza

Komatsu

et al. 2008

Experimental Gerontology

Self Cite

View full text Add to dashboard Cite

Calorie restriction (CR) may modulate insulin signaling in response to energy intake through suppression of the growth hormone (GH)-IGF-1 axis. We investigated the glucose-stimulated serum insulin response and subsequent alterations in insulin receptor (IR), Akt, and FoxO1 in the rat liver and quadriceps femoris muscle (QFM). Nine-month-old wild type (W) male Wistar rats fed ad libitum (AL) or a 30% CR diet initiated at 6 weeks of age and GH-suppressed transgenic (Tg) rats fed AL were killed 15 min after intraperitoneal injection of glucose or saline. In W-AL rats, the serum insulin concentration was elevated by glucose injection. Concomitantly, the phosphorylated (p)-IR and p-Akt levels were increased in both tissues. The active FoxO1 level was decreased in the liver, but not significantly in the QFM. In W-CR and Tg-AL rats, the serum insulin response was lower, and no significant changes were

show abstract

Section: Introductionmentioning

confidence: 59%

Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Calorie restriction minimizes activation of insulin signaling in response to glucose: Potential involvement of the growth hormone-insulin-like growth factor 1 axis

Hayashi

Yamaza

Komatsu

et al. 2008

Experimental Gerontology

Self Cite

View full text Add to dashboard Cite

show abstract

“…In our previous study, we demonstrated that long-lived W-CR and Tg-AL rats exhibited normal or slightly improved glucose tolerance with lower serum insulin responses (Yamaza et al 2004). Subsequent analyses have shown that CR modulates the activation of insulin signaling in response to glucose loading in a tissue-specific manner.…”

Section: Discussionmentioning

confidence: 99%

“…Our previous study demonstrated that W-CR and Tg-AL rats had normal or slightly improved glucose tolerance without a significant surge in the serum insulin concentration after a glucose load (Yamaza et al, 2004). In a similar experimental setting, we also showed that the activation of insulin signaling in response to glucose was minimized in the liver, while similar findings were observed in the skeletal muscle in W-CR and Tg-AL rats, in comparison with the findings in W-AL rats , suggesting a role for the GH-IGF-1 axis in the effect of CR.…”

Section: Introductionmentioning

confidence: 99%

Divergent regulation of adipose tissue metabolism by calorie restriction and inhibition of growth hormone signaling

Park

Komatsu

Hayashi

et al. 2009

Experimental Gerontology

Self Cite

View full text Add to dashboard Cite

Calorie restriction (CR) and a reduced growth hormone (GH) signal affect insulin sensitivity and lifespan in mammals in a similar manner. We investigated the effects of CR and moderate inhibition of GH on glucose-stimulated activation of insulin signaling and the expression of genes related to fat metabolism in white adipose tissue (WAT) in rats. We used 10-month-old male, wild-type (W) Wistar rats, fed ad libitum (AL) or a 30% CR diet from 6 weeks of age, and transgenic (Tg) rats with moderately suppressed GH signaling.Rats were killed 15 min after an intraperitoneal injection of glucose or saline. In control W-AL rats, the levels of serum insulin, phosphorylated (p) insulin receptor (pY-IR), p-Akt, and the expression of glucose transporter (Glut) 4 in the membrane fraction were greater in the glucose-injected group than in the saline-injected group, indicating significant activation of insulin signaling in response to glucose loading. In the W-CR and Tg-AL rats, the serum insulin and pY-IR levels were lower than those in the W-AL rats. The Akt-Glut pathway was up-regulated even after saline-injection. Expression levels of adipogenic and lipogenic genes including PPAR, adiponectin, and its receptors, were higher in the W-CR rats than in the W-AL and Tg-AL rats. The present findings indicate adipose tissue metabolic profiles specific to CR.

show abstract

Caloric Restriction, Longevity, and Adiposity

Redman

Ravussin

2010

Adipose Tissue in Health and Disease

View full text Add to dashboard Cite

A transgenic dwarf rat model as a tool for the study of calorie restriction and aging

Cited by 28 publications

References 6 publications

Calorie restriction minimizes activation of insulin signaling in response to glucose: Potential involvement of the growth hormone-insulin-like growth factor 1 axis

Calorie restriction minimizes activation of insulin signaling in response to glucose: Potential involvement of the growth hormone-insulin-like growth factor 1 axis

Divergent regulation of adipose tissue metabolism by calorie restriction and inhibition of growth hormone signaling

Caloric Restriction, Longevity, and Adiposity

Contact Info

Product

Resources

About