Comparative studies of effects of dehydroepiandrosterone on rat and chicken liver

Bobyleva, Valentina; Kneer, Nancy; Bellei, Monica; Battelli, Daniele; Muscatello, Umberto; Lardy, Henry A.

doi:10.1016/0305-0491(93)90100-j

Cited by 5 publications

(2 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to recent research [8], it is possible that DHEA activates hepatic mitochondria through the action of liver proteins, which enhance RNA transcription and subsequent protein synthesis, resulting in a higher relative liver weight than is evident in control-fed birds. However, the results of this study are in disagreement with those of Bobyleva et al [27], which showed that DHEA did not significantly decrease body and liver weight in chickens. This discrepancy may be explained by the different breed and age of chickens used in the two studies.…”

Section: Discussioncontrasting

confidence: 99%

Effects of Dehydroepiandrosterone (DHEA) on Hepatic Lipid Metabolism Parameters and Lipogenic Gene mRNA Expression in Broiler Chickens

Tang

Zou

2007

Lipids

View full text Add to dashboard Cite

The aim of the present study was to identify the effects of dehydroepiandrosterone (DHEA) on hepatic lipid metabolism parameters and lipogenic gene mRNA expression in broiler chickens. A total of 72 1-day-old broiler chicks received a common basal diet with DHEA added at either 0 (control), 5 or 20 mg/kg feed. In the present study, the hepatic triglyceride (TG) concentration was significantly lower in male and female broilers that had bed administered DHEA than in control birds. In contrast, DHEA administration caused a marked rise in the hepatic non-esterified fatty acid (NEFA) concentration in both male and female broilers and also increased lipase (HL) activity in male broilers, while in female birds, no significant differences were observed in HL activity. The expression of peroxisome proliferators-activated receptor alpha (PPARalpha) and carnitine palmitoyl transferase I (CPTI) mRNA was decidedly enhanced following treatment with DHEA, and a similar tendency was also observed in the expression of acyl-Coenzyme A oxidase 1 (ACOX1). However, no significant differences were observed in the expression of either sterol regulatory element binding protein-1c (SREBP-1c) or acetyl CoA carboxylase (ACC) mRNA, except for a decline in the expression of ACC in females treated with 5 mg DHEA/kg. Numerous peroxisomes without a core and an increased number of peroxisomes were evident during morphological observations of broiler livers, in animals that had been treated with DHEA. Overall, the results of the present study indicated that DHEA accelerated lipid catabolism by direct regulation of hepatic lipid metabolism and by induction of relevant gene expression.

show abstract

Section: Discussioncontrasting

confidence: 99%

Effects of Dehydroepiandrosterone (DHEA) on Hepatic Lipid Metabolism Parameters and Lipogenic Gene mRNA Expression in Broiler Chickens

Tang

Zou

2007

Lipids

View full text Add to dashboard Cite

show abstract

“…Recent studies in our laboratory (16,17) and in others (18) have characterised DHEA as a fat-reducing agent in broiler chickens. Chickens fed DHEA exhibited decreased hepatic TAG synthesis and plasma transport, and accelerated liver lipid mobilisation through the regulation of the hepatic lipid metabolic pathways and the expression of the relevant genes involved.…”

mentioning

confidence: 99%

Dehydroepiandrosterone activates cyclic adenosine 3′,5′-monophosphate/protein kinase A signalling and suppresses sterol regulatory element-binding protein-1 expression in cultured primary chicken hepatocytes

Tang

Shen

et al. 2009

Br J Nutr

View full text Add to dashboard Cite

Dehydroepiandrosterone (DHEA), a steroid hormone that is secreted by the adrenal cortex in mammals, has an array of biological actions, including inhibition of fat synthesis, decreasing the number of adipocytes, and a reduction in mammalian metabolic efficiency. Recent studies showed that DHEA may decrease fat deposition in poultry, but the mechanism of action is unclear. In the present study, we demonstrate that DHEA stimulates intracellular cyclic adenosine 3 0 ,5 0 -monophosphate (cAMP) accumulation in chicken hepatocytes during a 30 min incubation period. Increases in intracellular cAMP are evoked by as low as 0·1 mM-DHEA. The cAMP induced by DHEA, while suppressing cAMP-specific phosphodiesterase activity, also activates cAMP-dependent protein kinase A (PKA) in chicken hepatocytes. In addition, the activation of PKA leads to down-regulation of sterol regulatory element-binding protein-1 (SREBP-1). These findings demonstrate that direct action by DHEA leads to activation of the cAMP/PKA signalling system in the modulation of lipid metabolism by repressing SREBP-1, thereby providing a novel explanation for some of the underlying effects proposed for DHEA in the prevention of fat deposition in poultry.Dehydroepiandrosterone: Hepatic lipid metabolism: Lipogenesis: Cultured primary chicken hepatocytes Cyclic adenosine 3 0 ,5 0 -monophosphate (cAMP) is an integral constituent of the kinase cascade that links a number of extracellular signals to a variety of cellular functions. Under physiological conditions, the biosynthesis of lipids in the liver is negatively regulated, at least in part, by the elevated intracellular level of cAMP (1 -3) . Glucagon, the adrenalines, and other reagents raise the cellular cAMP concentration level and reduce the activity or level of hepatic lipogenic enzymes (4,5) such as fatty acid synthase, stearoyl-CoA desaturase, and glycerol-3-phosphate acyltransferase. The cAMPdependent kinase, protein kinase A (PKA), which is a major protein kinase activated by cAMP, has been shown to be involved in lipid metabolism as well (6,7) . Hepatic fatty acid synthesis and fatty acid synthesis in cultured hepatocytes, mediated by sterol regulatory element-binding protein (SREBP)-1, a transcription factor that regulates genes controlling intracellular lipid metabolism, have been shown to be negatively affected by cAMP (8) . It has also been demonstrated that cAMP inhibits insulin-regulated SREBP-1 mRNA levels and the expression of the SREBP-1-regulated genes involved in lipogenesis (9) . However, the molecular mechanism underlying this inhibitory function is still unclear.Dehydroepiandrosterone (DHEA), the most abundant steroid hormone in circulation (10)

show abstract

Effects of In Ovo Administration of DHEA on Lipid Metabolism and Hepatic Lipogenetic Genes Expression in Broiler Chickens During Embryonic Development

Zhao

Zou

2007

Lipids

View full text Add to dashboard Cite

In order to study the mechanism of DHEA (Dehydroepiandrosterone) in reducing fat in broiler chickens during embryonic development, fertilized eggs were administrated with DHEA before incubation and its effect on lipid metabolism and expression of hepatic lipogenetic genes was investigated. The mRNA levels of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME), apolipoprotein B100 (apoB100) and sterol regulator element binding protein-1c (SREBP-1c) were determined using real time quantitative PCR. Samples of livers were collected from the chickens on days 9, 14, and 19 of embryonic development as well as at hatching. Blood samples were extracted on days 14, 19 of incubation and at hatching. The results showed that DHEA decreased the concentration of triacyglycerol in the blood and the content in liver, and the mRNA levels of ACC, FAS, ME, SREBP-1c and apoB. This suggested that DHEA decreased the expression of hepatic lipogenetic genes and suppressed triglycerols transport, by which it reduced the deposition of fat in adipose tissue in broiler chickens during embryonic development and hatching.

show abstract

Comparative studies of effects of dehydroepiandrosterone on rat and chicken liver

Cited by 5 publications

References 26 publications

Effects of Dehydroepiandrosterone (DHEA) on Hepatic Lipid Metabolism Parameters and Lipogenic Gene mRNA Expression in Broiler Chickens

Effects of Dehydroepiandrosterone (DHEA) on Hepatic Lipid Metabolism Parameters and Lipogenic Gene mRNA Expression in Broiler Chickens

Dehydroepiandrosterone activates cyclic adenosine 3′,5′-monophosphate/protein kinase A signalling and suppresses sterol regulatory element-binding protein-1 expression in cultured primary chicken hepatocytes

Effects of In Ovo Administration of DHEA on Lipid Metabolism and Hepatic Lipogenetic Genes Expression in Broiler Chickens During Embryonic Development

Contact Info

Product

Resources

About