The Effect of Linseed on Intramuscular Fat Content and Adipogenesis Related Genes in Skeletal Muscle of Pigs

Abstract

The aim of the study was to investigate the effect of n-3 PUFA enrichment in longissimus muscle on intramuscular fat (IMF) content and expression of related genes in growing-finishing barrows. Two isoenergetic, isonitrogenous and isolipidic diets were formulated: one was basal diet and the other contained 10% linseed. Twenty-four Landrace x NewDamLine barrows weighing 35 +/- 3.7 kg were randomly assigned to four treatment groups with six pigs per group. During the whole experimental period of 90 days, all groups were first fed the basal diet and then the linseed diet for 0, 30, 60, and 90 days before slaughter, respectively. Meat quality, fatty acid composition, and expression of genes involved in adipogenesis in longissimus muscle were measured and analyzed. The IMF content increased linearly (P < 0.05) as the linseed diet feeding time prolonged. Meanwhile, n-3 PUFA content and expression of peroxisome proliferator-activated receptor delta (PPARdelta), PPARgamma, adipocyte fatty acid-binding protein (aP2) and lipoprotein lipase (LPL) increased linearly (P < 0.01) as well, while the expression of wingless related MMTV integration site 10b (Wnt10b) linearly decreased (P < 0.01). Furthermore, significant (P < 0.01) quadratic or linear relation was observed between n-3 PUFA enrichment and expression of these genes, while significant (P < 0.01) quadratic or linear relation was observed between the expression of PPARgamma, aP2 or Wnt10b and IMF content. These data show that enhancing n-3 PUFA enrichment in muscle leads to significant increase in IMF content. A possible explanation is due to alterations in the expression of genes involved in adipogenesis, however this will need to be confirmed by protein and enzyme activity studies.

Nutritional intervention during gestation alters growth, body composition and gene expression patterns in skeletal muscle of pig offspring

“…Treatment E offspring had a lower IMF in the SM compared with control but had no observable difference in PPAR-g expression. This is in contrast to Luo et al (2009), who showed a positive relationship between PPAR-g and IMF in pigs using a 10% linseed diet. Instead, this study noted a decrease in PPAR-d levels in Treatment E offspring.…”

“…PPAR-d plays a role in lipid oxidation (Tanaka et al, 2003) and has also been implicated in regulating adipogenesis in mouse myoblasts (Yu et al, 2008). However, according to Luo et al (2009), PPAR-g is more closely related to IMF content than PPAR-d and in our study PPAR-g remained unchanged between treatments.…”

“…Whether IMF is influenced by PPAR-d levels is unknown. Luo et al (2009), suggest that PPAR-d is not directly involved in IMF, but can activate PPAR-g through n-3 polyunsaturated fatty acid enrichment. The drip loss 24 to 48 h of the SM muscle was increased and therefore the water-holding capacity reduced in Treatment E offspring compared with the control.…”

Effect of different dietary oil sources on the growth performance, blood characteristics, fatty acid profiles, and expression of lipogenic genes in the liver of broiler chickens

“…Lipids were extracted from the liver tissue samples using chloroform/methanol (1 : 1 v/v) by a modified method of Folch et al (1957). Fatty acid methyl esters were prepared for gas chromatography determination using KOH/methanol (Luo et al 2009). …”

Effects of the replacement of corn oil with linseed oil on fatty acid composition and the expression of lipogenic genes in broiler chickens

“…Dietary fatty acids are absorbed by monogastric animals and deposited in their tissues, n-6 and n-3 PUFAs are competitively metabolized by the same pathway (Luo et al 2009). So, there is a considerable potential for the manipulation of the fatty acid profiles of poultry tissue by dietary means, thus to increase the supply of n-3 PUFA (especially EPA and DHA), and to regulate n-6/n-3 PUFA ratio to a level which is suitable for human consumption.…”