The Effect of Fasting/Refeeding and Insulin Treatment on the Expression of the Regulatory Genes of Ketogenesis in Intestine and Liver of Suckling Rats

Arroyo, Gladys Arias; Asins, Guillermina; Hegardt, Fausto G.; Serra, Dolors

doi:10.1006/abbi.1997.9911

Cited by 20 publications

(15 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present results further indicate that the three CPT 1 isoforms could play different roles in providing energy under fasting via fatty acid β-oxidation. Similarly, fasting up-regulates the gene expression and activity of CPT 1 in the liver in both mammals and fish (Arias et al, 1997;Boukouvala et al, 2010;Morash and McClelland, 2011;Ryu et al, 2005;Skiba-Cassy et al, 2007). In the CPT enzyme system, CPT 1 is controlled by a malonyl-CoA-dependent mechanism, while CPT 2 is controlled by a malonyl-CoA-independent mechanism.…”

Section: Discussionmentioning

confidence: 98%

Molecular characterization and nutritional regulation of carnitine palmitoyltransferase (CPT) family in grass carp (Ctenopharyngodon idellus)

Shi

Sun

Zhou

et al. 2017

Comparative Biochemistry and Physiology Part B: Biochemistry an

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 98%

Molecular characterization and nutritional regulation of carnitine palmitoyltransferase (CPT) family in grass carp (Ctenopharyngodon idellus)

Shi

Sun

Zhou

et al. 2017

Comparative Biochemistry and Physiology Part B: Biochemistry an

View full text Add to dashboard Cite

“…Although the activity of CPTI is mostly controlled by allosteric inhibition by malonyl-CoA (32), significant regulation also takes place at the gene expression level. A glucocorticoiddependent upregulation, combined with negation of the insulin-dependent downregulation, will cause a major increase in CPTI expression during fasting (39,40). This effect may be so strong as to blunt any further increase mediated by PPARα.…”

Section: Discussionmentioning

confidence: 99%

Peroxisome proliferator–activated receptor α mediates the adaptive response to fasting

Kersten¹,

Seydoux²,

Peters³

et al. 1999

J. Clin. Invest.

1,468

1,259

View full text Add to dashboard Cite

Prolonged deprivation of food induces dramatic changes in mammalian metabolism, including the release of large amounts of fatty acids from the adipose tissue, followed by their oxidation in the liver. The nuclear receptor known as peroxisome proliferator-activated receptor α (PPARα) was found to play a role in regulating mitochondrial and peroxisomal fatty acid oxidation, suggesting that PPARα may be involved in the transcriptional response to fasting. To investigate this possibility, PPARα-null mice were subjected to a high fat diet or to fasting, and their responses were compared with those of wildtype mice. PPARα-null mice chronically fed a high fat diet showed a massive accumulation of lipid in their livers. A similar phenotype was noted in PPARα-null mice fasted for 24 hours, who also displayed severe hypoglycemia, hypoketonemia, hypothermia, and elevated plasma free fatty acid levels, indicating a dramatic inhibition of fatty acid uptake and oxidation. It is shown that to accommodate the increased requirement for hepatic fatty acid oxidation, PPARα mRNA is induced during fasting in wildtype mice. The data indicate that PPARα plays a pivotal role in the management of energy stores during fasting. By modulating gene expression, PPARα stimulates hepatic fatty acid oxidation to supply substrates that can be metabolized by other tissues. J. Clin. Invest. 103:1489-1498 (1999).adipose tissue (BAT) and the liver, and to a lesser extent in the kidneys, skeletal muscle, and heart (10). Of the 3 isotypes, PPARα has been the best characterized, a fortunate consequence of the availability of PPARα-null mice (16). Studies with these mice have demonstrated that PPARα controls the expression of numerous genes related to lipid metabolism in the liver, including genes involved in mitochondrial β-oxidation, peroxisomal β-oxidation, fatty acid uptake and/or binding, and lipoprotein assembly and transport (17)(18)(19). Several functional consequences of lowered gene expression levels were observed: PPARα-null mice are refractory to peroxisome proliferators, and male mice appeared to be overly sensitive to etomoxir, an inhibitor of carnitine palmitoyltransferase I (CPTI) (16,20). A striking metabolic defect was observed in aged (8-month-old) PPARα-null mice, characterized by a sexually dimorphic dyslipidemia with pronounced adiposity in females and steatosis in males (21). Despite this great expansion of our understanding of the function of PPARα, what remains unclear is when and how, in an intact organism, the PPARα signaling pathways are triggered, and how this specifically affects lipid and carbohydrate metabolism.One physiological condition during which PPARα-dependent signaling should become challenged is fasting, because (a) huge amounts of fatty acids are delivered to the liver to be oxidized; (b) once taken up, fatty acids have to be delivered to the mitochondria for oxidation; and (c) β-oxidation is accelerated in conjunction with increased synthesis of ketone bodies.A second physiological stimulus that may challenge t...

show abstract

“…Further, as it occurred at a time when the expression of Complex III of the mitochondrial respiratory chain and of mitochondrial HMG-CoA synthase was increased specifi cally in the jejunum (and not in the liver), it is reasonable to assume that the increase in BHB production occurred in the jejunum and not in the liver. Whereas the liver is considered to be the major ketogenic organ ( 44 ), FAO and ketogenesis also occur in the small intestine during suckling. Accordingly, mHMGCoAS2 is highly expressed in the small intestine of suckling rats ( 40,45 ), and the small intestine regains its ketogenic capacity when pups are weaned onto, or when adult animals are adapted to a HFD ( 40 ).…”

Section: Discussionmentioning

confidence: 99%

Diacylglycerol acyltransferase-1 inhibition enhances intestinal fatty acid oxidation and reduces energy intake in rats

Schober

Arnold

Birtles

et al. 2013

Journal of Lipid Research

View full text Add to dashboard Cite

( 1, 2 ). Often an overconsumption of energy-dense, fat-rich food leads to excessive triacylglycerol (TAG) accumulation in adipose and nonadipose tissue. This can result in insulin resistance and nonalcoholic fatty liver disease, emphasizing the need for pharmacotherapeutic approaches that are effective when a high-fat diet (HFD) is consumed ( 3 ).In the small intestine dietary TAGs are hydrolyzed to 2-monoacylglycerols (MAGs) and fatty acids (FAs) that are absorbed . Specifi c binding proteins in the enterocytes shuttle MAG and FFA to the endoplasmic reticulum for reesterifi cation. This involves the acylation from MAG to sn -1,2-diacylglycerol (DAG) by MAG acyltransferase and the acylation from DAG to TAG catalyzed by acyl CoA:diacylglycerol acyltransferase-1 (DGAT-1) (EC 2.3.1.20 ), the rate-limiting step in TAG synthesis ( 4 ). This MAG pathway is important after eating, when intestinal MAG levels are high ( 5 ). DGAT-1 is one of two known DGAT enzymes ( 6 ) in tissues associated with TAG synthesis, including the small intestine ( 6, 7 ), where DGAT-1 is involved in fat absorption, lipoprotein assembly, and regulation of plasma TAG concentrations ( 7 ). DGAT-1 knockout (dgat-1 Obesity is a global epidemic and a major risk factor for type 2 diabetes, hypertension, cardiovascular disease, and other ailments. The development of obesity is multifactorial 28 February 2013. Published, JLR Papers in Press, February 28, 2013 DOI 10.1194 Diacylglycerol acyltransferase-1 inhibition enhances intestinal fatty acid oxidation and reduces energy intake in rats Abbreviations: AMPK ␣ , AMP-activated protein kinase-␣ ; ASP, acid soluble products; AUC, area under the curve; BHB, ␤ -hydroxybutyrate; BT, body temperature; BW, body weight; CFA, conditioned fl avor avoidance; CPT-1, carnitine palmitoyltransferase-1; DAG, sn -1,2-diacylglycerol; DGAT-1, acyl-CoA:diacylglycerol acyltransferase-1; DGAT-1i, diacylglycerol acyltransferase-1 inhibitor; dgat-1 Ϫ / Ϫ This work was supported by Swiss National Science Foundation Grant 31_130665 (W.L.). Manuscript received 19 December 2012 and in revised form

show abstract

The Effect of Fasting/Refeeding and Insulin Treatment on the Expression of the Regulatory Genes of Ketogenesis in Intestine and Liver of Suckling Rats

Cited by 20 publications

References 43 publications

Molecular characterization and nutritional regulation of carnitine palmitoyltransferase (CPT) family in grass carp (Ctenopharyngodon idellus)

Molecular characterization and nutritional regulation of carnitine palmitoyltransferase (CPT) family in grass carp (Ctenopharyngodon idellus)

Peroxisome proliferator–activated receptor α mediates the adaptive response to fasting

Diacylglycerol acyltransferase-1 inhibition enhances intestinal fatty acid oxidation and reduces energy intake in rats

Contact Info

Product

Resources

About