• Asian-Australasian Journal of Animal Sciences
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• 제32권5호
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• pp.648-656
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• 2019

Objective: An experiment was conducted to determine the effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in cows during the transition period. Methods: Thirty-nine Holstein dry cows were blocked and assigned randomly to three groups, fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation $[NE_L]/kg$ dry matter [DM]), a medium energy density diet (MD, $1.47Mcal\;NE_L/kg\;DM$), or a low energy density diet (LD, $1.30Mcal\;NE_L/kg\;DM$) prepartum; they were fed the same lactation diet to 28 days in milk (DIM). All the cows were housed in a free-stall barn and fed ad libitum. Results: The reduced energy density diets decreased the blood insulin concentration and increased nonesterified fatty acids (NEFA) concentration in the prepartum period (p<0.05). They also increased the concentrations of glucose, insulin and glucagon, and decreased the concentrations of NEFA and ${\beta}-hydroxybutyrate$ during the first 2 weeks of lactation (p<0.05). The plasma urea nitrogen concentration of both prepartum and postpartum was not affected by dietary energy density (p>0.05). The dietary energy density had no effect on mRNA abundance of insulin receptors, leptin and peroxisome proliferator-activated $receptor-{\gamma}$ in adipose tissue, and phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase-1 and peroxisome proliferator-activated $receptor-{\alpha}$ in liver during the transition period (p>0.05). The HD cows had higher mRNA abundance of hormone-sensitive lipase at 3 DIM compared with the MD cows and LD cows (p = 0.001). The mRNA abundance of hepatic pyruvate carboxy-kinase at 3 DIM tended to be increased by the reduced energy density of the close-up diets (p = 0.08). Conclusion: The reduced energy density diet prepartum was effective in controlling adipose tissue mobilization and improving the capacity of hepatic gluconeogenesis postpartum.

• Journal of Ginseng Research
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• 제34권4호
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• pp.369-375
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• 2010

This study evaluated the protective effects of ginseng leaf extract (GLE) against high fat-diet-induced hyperglycemia and hyperlipidemia, and explored the potential mechanism underlying these effects in C57BL/6J mice. The mice were randomly divided into four groups: normal control, high fat diet control (HFD), GLE-treated at 250 mg/kg, and GLE-treated at 500 mg/kg. To induce hyperglycemic and hyperlipidemic states, mice were fed a high fat diet for 6 weeks and then administered GLE once daily for 8 weeks. At the end of the treatment, we examined the effects of GLE on plasma glucose, lipid levels, and the expression of genes related to lipogenesis, lipolysis, and gluconeogenesis. Both GLE groups lowered levels of plasma glucose, insulin, triglycerides, total cholesterol, and non-esterified fatty acids when compared to those in HFD group. Histological analysis revealed significantly fewer lipid droplets in the livers of GLE-treated mice compared with HFD mice. To elucidate the mechanism, Western blots and RT-PCR were performed using liver tissue. Compared with HFD mice, GLE-treated mice showed higher levels of phosphorylation of AMP-activated protein kinase (AMPK) and its substrate, acetyl-CoA carboxylase, but no differences in the expression of lipogenic genes such as sterol regulatory element-binding protein 1a, fatty acid synthase, sterol-CoA desaturase 1 and glycerol-3-phosphate acyltransferase. However, the expression levels of lipolysis and fatty acid uptake genes such as peroxisome proliferator-activated receptor-$\alpha$ and CD36 were increased. In addition, phosphoenolpyruvate carboxykinase gene expression was decreased. These results suggest that GLE ameliorates hyperglycemia and hyperlipidemia by inhibiting gluconeogenesis and stimulating lipolysis, respectively, via AMPK activation.

• 비만대사연구학술지
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• 제3권1호
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• pp.35-42
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• 2024

Serotonin, a biogenic amine widely found in many organisms, functions as both a neurotransmitter and hormone. Although serotonin is involved in various physiological processes, this study aimed to review its role in energy metabolism. Given that serotonin cannot cross the blood-brain barrier and is synthesized by two different isoforms of tryptophan hydroxylase in the central nervous system (CNS) and peripheral tissues, it is reasonable to assume that serotonin in the CNS and peripheral tissues functions independently. Recent studies have demonstrated how serotonin influences energy metabolism in metabolic target organs such as the intestines, liver, pancreas, and adipose tissue. In summary, serotonin in the CNS induces satiety and appetite suppression, stimulates thermogenesis, and reduces body weight. Conversely, serotonin in the periphery increases intestinal motility, stimulates gluconeogenesis in the liver, suppresses glucose uptake by hepatocytes, promotes fat uptake by liver cells, stimulates insulin secretion while suppressing glucagon secretion in the pancreatic islets, promotes lipogenesis in white adipose tissue, inhibits lipolysis and browning of white adipose tissue, and suppresses thermogenesis in brown adipose tissue, thereby storing energy and increasing body weight. However, considering that most experimental results were obtained using mice and conducted under specific nutritional conditions, such as high-fat diets, whether serotonin acts in the same way in humans, whether it will act similarly in individuals with normal versus obese weights, and whether its effects vary depending on the type of food consumed, remain unknown.