Effect of feed restriction on adipose tissue transcript concentrations in genetically lean and obese pigs.

Abstract

To determine possible genetic influences on the steady-state concentrations of several key transcription factor transcripts and the transcript concentrations for adipocyte-characteristic proteins, young, genetically obese and lean pigs were given ad libitum access or feed or were restrictively fed at 50% of ad libitum intake for 5 wk. Obese pigs were smaller and fatter than lean pigs, whether intake was ad libitum or restrictive. Plasma protein, albumin, and cholesterol concentrations were greater in obese than in lean pigs. Plasma NEFA, blood urea nitrogen, triacylglycerols, and postprandial glucose and insulin concentrations were less (P < .02) in pigs fed restrictively than in pigs with ad libitum access to feed, regardless of genetic group. The adipose tissue glucose transporter 4, fatty acid synthase, and leptin transcript concentrations were greater (P < .05) in obese than in lean pigs. The CCAAT/enhancer binding proteins beta and alpha, adipocyte fatty acid binding protein, hormone-sensitive lipase, and the beta1-adrenergic receptor transcript concentrations tended (P < . 10) to be greater in adipose tissue from obese than in that from lean pigs. Several other transcripts were numerically greater in obese than in lean pigs. The data collectively suggest that messenger RNA concentration for several adipose tissue proteins is a contributing factor to the excess fat deposition in these obese pigs. Restricted feeding did not change the concentration of any transcript except that for adipocyte fatty acid binding protein, which was reduced. The accretion of fat was markedly reduced in the restrictively fed pigs, but this diminution does not seem to be regulated by modulation of messenger RNA concentration.

The effect of breed and feeding level on carcass composition, fatty acid profile and expression of genes encoding enzymes involved in fat metabolism in two muscles of pigs fed a diet enriched in n-3 fatty acids. A preliminary study

“…This finding is not in agreement with the results of McNeel et al (2000), who stated that PPARG gene expression in subcutaneous adipose tissue of genetically obese crossbreed (Duroc x Yorkshire) pigs was slightly higher than in genetically lean animals. The significantly lower expression of the FABP4 gene in the BF muscle in pigs fed at the lower level of feed intake, found in our study, is not in line with the increased expression of this gene in pigs fed at the 50% restriction level reported by McNeel et al (2000).…”

“…This finding is not in agreement with the results of McNeel et al (2000), who stated that PPARG gene expression in subcutaneous adipose tissue of genetically obese crossbreed (Duroc x Yorkshire) pigs was slightly higher than in genetically lean animals. The significantly lower expression of the FABP4 gene in the BF muscle in pigs fed at the lower level of feed intake, found in our study, is not in line with the increased expression of this gene in pigs fed at the 50% restriction level reported by McNeel et al (2000). Otherwise, our results on greater FABP4 expression in the BF muscle of more fatty L990 pigs are partly in agreement with results of Damon et al (2006), who found that in the LD muscle of crossbreed (Large White x Duroc) barrows, the FABP-4 protein content was two-fold greater in pigs with a high IMF content than those with a low content.…”

Slow Growing Pre-Weaning Piglets Have Altered Adipokine Gene Expression

“…The majority of adipose tissue deposition in swine is subcutaneous and this is reflected in the accumulation of SQ LPL mRNA in the present study, which is a marker for adipocyte differentiation and lipid metabolism [16] [24] [25]. Slower growing piglets had less SQ LPL mRNA abundance than fast growing piglets.…”

“…These genes were selected as they all have been demonstrated to be expressed by adipose tissue from swine, as previously described in the Introduction, and their ontogeny of development in neonatal adipose tissue has been characterized [10]. Leptin, adiponectin, lipoprotein lipase (LPL) and fatty acid synthase (FAS) were selected because they are markers for adipose differentiation in swine [16]. The interleukins 1β, 6 and 15 were included because they have been identified by Hausman et al [9] to be expressed by neonatal pig adipose tissue using proteomic analysis.…”

Leptin concentration in blood and its hypothalamic binding are poorly related with amount of fat and growth rate in pigs

“…Under experimental conditions it decreases feed intake (Barb et al, 1998;Velkoska et al, 2003). The amount of the produced and secreted leptin may depend on hormonal and nutritional factors (Zhang et al, 1994;Saladin et al, 1995;Cameron et al, 2000Cameron et al, , 2003McNeel et al, 2000). This substance informs the central nervous system about the metabolism of the fatty tissue and the amount of stored lipids (Campfield et al, 1995;Meister, 2000).…”