Effects of habitual exercise and diet restriction on the hepatic fat accumulation in Zucker fatty rats

Kurosaka, Yuka; Kitamura, Hiromi; Yamauchi, Hideki; Shiroya, Yoko; Minato, Kumiko

doi:10.7600/jspfsm.63.223

Cited by 3 publications

(6 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many studies have reported that skeletal muscle loss and fatty liver are closely related and that hepatic fat accumulation increases in sarcopenia patients and sedentary subjects [ 10 , 11 , 12 ]. We recently characterized the effects of habitual exercise and/or diet restriction on hepatic fat accumulation in Zucker fatty (ZF) rats [ 13 , 14 ]. ZF rats have a mutation in the leptin receptor gene that causes increased appetite and weight gain [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

“…Previously, we found that dietary restriction in ZF rats did not ameliorate the development of fatty liver but rather accelerated it. We also found that the same dietary restriction combined with physical exercise prevented intrahepatic fat accumulation and maintained a healthy liver [ 13 ]. Moreover, in previous studies focusing on fat cell size, it was shown that a combination of exercise and dietary restriction in ZF rats suppresses fat cell size hypertrophy and prevents fatty liver [ 14 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Protective Effects of Voluntary Exercise on Hepatic Fat Accumulation Induced by Dietary Restriction in Zucker Fatty Rats

Kurosaka

Machida

Shiroya

et al. 2021

IJMS

Self Cite

View full text Add to dashboard Cite

Weight control based on dietary restriction (DR) alone can cause lipid metabolic failure and progression to fatty liver. This study aimed to investigate the effect of exercise on preventing DR-induced hepatic fat accumulation in Zucker fatty (ZF) rats by focusing on the relationship between adipose tissue lipolysis and hepatic fat uptake. Six-week-old male ZF rats were randomly assigned to obese, DR, or DR with exercise (DR + Ex) groups. The DR and DR + Ex groups were fed a restricted diet, with the latter also undergoing voluntary exercise. After 6 weeks, hepatic fat accumulation was observed in the DR group, whereas intrahepatic fat was markedly reduced in the DR + Ex group. Compared with the obese (Ob) group, the DR group exhibited 2.09-fold expression of hepatic fatty acid translocase (FAT)/CD36 proteins (p < 0.01) and 0.14-fold expression of hepatic fatty acid-binding protein (FABP)1 (p < 0.01). There were no significant differences between the DR + Ex group and the Ob group. FAT/CD36 and hepatic triglyceride (TG) expression levels were strongly positively correlated (r = 0.81, p < 0.001), whereas there was a strong negative correlation between FABP1 and hepatic TG expression levels (r = −0.65, p < 0.001). Our results suggest that hepatic fat accumulation induced by DR in ZF rats might be prevented through exercise-induced modifications in FAT/CD36 and FABP1 expression.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Protective Effects of Voluntary Exercise on Hepatic Fat Accumulation Induced by Dietary Restriction in Zucker Fatty Rats

Kurosaka

Machida

Shiroya

et al. 2021

IJMS

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, few reports have examined these effects simultaneously. We recently characterized the effects of habitual exercise and/or diet restriction on hepatic fat accumulation in Zucker fatty (ZF) rats [ 10 ]. Histologically, the intrahepatic accumulation of triglycerides (TGs) was suppressed by habitual exercise, but not by dietary restriction alone [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

“…We recently characterized the effects of habitual exercise and/or diet restriction on hepatic fat accumulation in Zucker fatty (ZF) rats [ 10 ]. Histologically, the intrahepatic accumulation of triglycerides (TGs) was suppressed by habitual exercise, but not by dietary restriction alone [ 10 ]. ZF rats have a mutation in the leptin receptor gene that causes increased appetite and weight gain; thus, they are used as an animal model of obesity [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

Effects of habitual exercise and dietary restriction on intrahepatic and periepididymal fat accumulation in Zucker fatty rats

et al. 2015

Self Cite

View full text Add to dashboard Cite

BackgroundHabitual exercise and dietary restriction are commonly recommended to prevent or ameliorate obesity and lifestyle-related diseases, including fatty liver. This study investigated the effects of habitual exercise and dietary restriction on hepatic triglyceride (TG) levels, serum leptin levels, and histological adipocyte size in periepididymal adipose tissue from Zucker fatty (ZF) rats.MethodsSix-week-old male ZF rats were randomly assigned to one of three groups: sedentary (Sed), sedentary and dietary restriction (Sed + DR), and training and dietary restriction (Tr + DR). Male Zucker lean (L) rats were used as control animals. All rats had access to water and the allowed quantity of food ad libitum. The rats in the Sed + DR and Tr + DR groups were fed a 30% restricted diet, while those in the Tr + DR group exercised voluntarily on a wheel ergometer. After 12 weeks, the rats were sacrificed for a histological examination of their liver and periepididymal adipose tissue. Hepatic and serum TG, serum total cholesterol, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, free fatty acid, and leptin levels were also measured.ResultsThe hepatic TG levels were significantly higher in the Sed + DR group than in the L (P < 0.001) and Sed (P < 0.05) groups. By contrast, the hepatic TG levels in the Tr + DR group were significantly lower than those in the Sed (P < 0.05) and Sed + DR (P < 0.001) groups, but not significantly different from the L group values. The periepididymal adipocytes were significantly larger in the Sed, Sed + DR, and Tr + DR groups than in the L group (P < 0.001) and were significantly smaller in the Tr + DR group compared to the Sed and Sed + DR groups (P < 0.001).ConclusionsOur results suggest a relationship between lipid metabolism and the size of adipose cells in ZF rats. Exercising plays an important role in decreasing hepatic TG levels, serum leptin levels, and the size of adipose cells.

show abstract

“…They show low physical activity levels compared with ordinary rats and eventually develop fatty liver 17) . Kurosaka et al 18) found that dietary restriction in ZF rats did not ameliorate the development of fatty liver, but accelerated it. They also found that the same dietary restriction combined with physical exercise prevented intrahepatic fat accumulation and maintained a healthy liver.…”

Section: Differential Effects Of Dietary Condition and Physical Activitymentioning

confidence: 99%

Protective effects of dietary restriction and physical exercise on intrahepatic fat accumulation

Kurosaka

Yamauchi

Takemori

et al. 2018

JPFSM

Self Cite

View full text Add to dashboard Cite

This paper discusses the effects of dietary restriction and physical exercise on the maintenance of good health, focusing on intrahepatic fat accumulation, a type of ectopic fat accumulation. Excessive intrahepatic fat accumulation eventually progresses to fatty liver, which may evolve into liver cirrhosis and liver cancer. Physical exercise and dietary restriction are generally accepted as the major non-pharmacological remedies against intrahepatic fat accumulation. However, a combination of diet and physical activity has not necessarily shown expected synergistic or additive effects. In fact, dietary conditions antagonistically blocked the effect of physical activity on fatty liver, and physical inactivity adversely exacerbated the effect of dietary restriction on intrahepatic fat accumulation. These diverse combination effects, as well as etiology-dependent diversity in the activation of cellular signaling pathways leading to fatty liver, suggest the need to optimize remedies for the efficient amelioration and prevention of intrahepatic fat accumulation in a case-dependent manner. As a tentative step to constructing a prescription formula for optimal remedies, the probable advantage of physical exercise over dietary restriction at preventing fat spillover from adipose tissue to liver is noted.

show abstract

Effects of habitual exercise and diet restriction on the hepatic fat accumulation in Zucker fatty rats

Cited by 3 publications

References 23 publications

Protective Effects of Voluntary Exercise on Hepatic Fat Accumulation Induced by Dietary Restriction in Zucker Fatty Rats

Protective Effects of Voluntary Exercise on Hepatic Fat Accumulation Induced by Dietary Restriction in Zucker Fatty Rats

Effects of habitual exercise and dietary restriction on intrahepatic and periepididymal fat accumulation in Zucker fatty rats

Protective effects of dietary restriction and physical exercise on intrahepatic fat accumulation

Contact Info

Product

Resources

About