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Bio F1B hamster: a unique animal model with reduced lipoprotein lipase activity to investigate nutrient mediated regulation of lipoprotein metabolism.

Cheema SK, Cornish ML - Nutr Metab (Lond) (2007)

Bottom Line: Fish oil feeding caused accumulation of apolipoproteinB48 containing lipoprotein particles suggesting hindrance of triglyceride-rich lipoprotein clearance.There was no significant effect of diet or strain on hepatic or intestinal microsomal triglyceride transfer protein activity indicating that hyperlipidaemia is not due to an increase in the assembly or secretion of lipoprotein particles.F1B hamsters showed significantly reduced levels of lipoprotein lipase activity, which was inhibited by fish oil feeding.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry, Memorial University, St, John's, NL, A1B 3X9, Canada. skaur@mun.ca.

ABSTRACT

Background: Bio F1B hamster is an inbred hybrid strain that is highly susceptible to diet-induced atherosclerosis. We previously reported that feeding a high fat fish oil diet to Bio F1B hamster caused severe hyperlipidaemia. In this study we compared the effects of various diets in the Bio F1B hamster and the Golden Syrian hamster, which is an outbred hamster strain to investigate whether genetic background plays an important role in dietary fat mediated regulation of lipoprotein metabolism. We further investigated the mechanisms behind diet-induced hyperlipidaemia in F1B hamster.

Methods: The Bio F1B and Golden Syrian hamsters, 8 weeks old, were fed high fat diets rich in either monounsaturated fatty acids, an n-6: n-3 ratio of 5 or a fish oil diet for 4 weeks. Animals were fasted overnight and blood and tissue samples were collected. Plasma was fractionated into various lipoprotein fractions and assayed for triacylglycerol and cholesterol concentrations. Plasma lipoprotein lipase activity was measured using radioisotope method. Microsomal triglyceride transfer protein activity was measured in the liver and intestine. Plasma apolipoproteinB48, -B100 and apolipoprotein E was measured using Western blots. Two-way ANOVA was used to determine the effect of diet type and animal strain.

Results: The fish oil fed F1B hamsters showed milky plasma after a 14-hour fast. Fish oil feeding caused accumulation of apolipoproteinB48 containing lipoprotein particles suggesting hindrance of triglyceride-rich lipoprotein clearance. There was no significant effect of diet or strain on hepatic or intestinal microsomal triglyceride transfer protein activity indicating that hyperlipidaemia is not due to an increase in the assembly or secretion of lipoprotein particles. F1B hamsters showed significantly reduced levels of lipoprotein lipase activity, which was inhibited by fish oil feeding.

Conclusion: Evidence is presented for the first time that alterations in lipoprotein lipase activity and mRNA levels contribute to varied response of these hamsters to dietary fat, highlighting the importance of genetic background in the regulation of lipid and lipoprotein metabolism by dietary fats. Bio F1B hamster may prove to be an important animal model to investigate nutrient mediated regulation of metabolic parameters under lipoprotein lipase deficiency.

No MeSH data available.


Related in: MedlinePlus

Hepatic (panel A) and intestinal (panel B) microsomal triglyceride transfer protein (MTTP) activity. The F1B (solid) and Golden Syrian (shaded) hamsters were fed fish oil (FO), monounsaturated fatty acid rich (MUFA) or N6:N3 diets. Animals were fed the specified diets for four weeks. Upon sacrifice, the liver and intestine were removed and snap frozen in liquid nitrogen and stored at -70°. Tissues were then analyzed for MTTP activity as described in the materials and methods section. Means for a variable with a different letter are significantly different (p < 0.05) by two-way ANOVA and the Newman-Keuls post-hoc test.
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Figure 5: Hepatic (panel A) and intestinal (panel B) microsomal triglyceride transfer protein (MTTP) activity. The F1B (solid) and Golden Syrian (shaded) hamsters were fed fish oil (FO), monounsaturated fatty acid rich (MUFA) or N6:N3 diets. Animals were fed the specified diets for four weeks. Upon sacrifice, the liver and intestine were removed and snap frozen in liquid nitrogen and stored at -70°. Tissues were then analyzed for MTTP activity as described in the materials and methods section. Means for a variable with a different letter are significantly different (p < 0.05) by two-way ANOVA and the Newman-Keuls post-hoc test.

Mentions: MTTP plays an important role in the assembly of lipoproteins originating from the liver (VLDL) and the intestine (chylomicrons). Thus, hepatic and intestinal MTTP activity was measured in F1B and GS hamsters fed various diets. There was no significant effect of diet (P = 0.15) or strain (P = 0.77) on hepatic MTTP activity (Figure 5A). Similarly, there was no significant effect of diet (P = 0.74) or strain (P = 0.31) on intestinal MTTP activity (Figure 5B). We also measured MTTP mRNA and protein levels however there was no significant effect of diet (data not given).


Bio F1B hamster: a unique animal model with reduced lipoprotein lipase activity to investigate nutrient mediated regulation of lipoprotein metabolism.

Cheema SK, Cornish ML - Nutr Metab (Lond) (2007)

Hepatic (panel A) and intestinal (panel B) microsomal triglyceride transfer protein (MTTP) activity. The F1B (solid) and Golden Syrian (shaded) hamsters were fed fish oil (FO), monounsaturated fatty acid rich (MUFA) or N6:N3 diets. Animals were fed the specified diets for four weeks. Upon sacrifice, the liver and intestine were removed and snap frozen in liquid nitrogen and stored at -70°. Tissues were then analyzed for MTTP activity as described in the materials and methods section. Means for a variable with a different letter are significantly different (p < 0.05) by two-way ANOVA and the Newman-Keuls post-hoc test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2235869&req=5

Figure 5: Hepatic (panel A) and intestinal (panel B) microsomal triglyceride transfer protein (MTTP) activity. The F1B (solid) and Golden Syrian (shaded) hamsters were fed fish oil (FO), monounsaturated fatty acid rich (MUFA) or N6:N3 diets. Animals were fed the specified diets for four weeks. Upon sacrifice, the liver and intestine were removed and snap frozen in liquid nitrogen and stored at -70°. Tissues were then analyzed for MTTP activity as described in the materials and methods section. Means for a variable with a different letter are significantly different (p < 0.05) by two-way ANOVA and the Newman-Keuls post-hoc test.
Mentions: MTTP plays an important role in the assembly of lipoproteins originating from the liver (VLDL) and the intestine (chylomicrons). Thus, hepatic and intestinal MTTP activity was measured in F1B and GS hamsters fed various diets. There was no significant effect of diet (P = 0.15) or strain (P = 0.77) on hepatic MTTP activity (Figure 5A). Similarly, there was no significant effect of diet (P = 0.74) or strain (P = 0.31) on intestinal MTTP activity (Figure 5B). We also measured MTTP mRNA and protein levels however there was no significant effect of diet (data not given).

Bottom Line: Fish oil feeding caused accumulation of apolipoproteinB48 containing lipoprotein particles suggesting hindrance of triglyceride-rich lipoprotein clearance.There was no significant effect of diet or strain on hepatic or intestinal microsomal triglyceride transfer protein activity indicating that hyperlipidaemia is not due to an increase in the assembly or secretion of lipoprotein particles.F1B hamsters showed significantly reduced levels of lipoprotein lipase activity, which was inhibited by fish oil feeding.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry, Memorial University, St, John's, NL, A1B 3X9, Canada. skaur@mun.ca.

ABSTRACT

Background: Bio F1B hamster is an inbred hybrid strain that is highly susceptible to diet-induced atherosclerosis. We previously reported that feeding a high fat fish oil diet to Bio F1B hamster caused severe hyperlipidaemia. In this study we compared the effects of various diets in the Bio F1B hamster and the Golden Syrian hamster, which is an outbred hamster strain to investigate whether genetic background plays an important role in dietary fat mediated regulation of lipoprotein metabolism. We further investigated the mechanisms behind diet-induced hyperlipidaemia in F1B hamster.

Methods: The Bio F1B and Golden Syrian hamsters, 8 weeks old, were fed high fat diets rich in either monounsaturated fatty acids, an n-6: n-3 ratio of 5 or a fish oil diet for 4 weeks. Animals were fasted overnight and blood and tissue samples were collected. Plasma was fractionated into various lipoprotein fractions and assayed for triacylglycerol and cholesterol concentrations. Plasma lipoprotein lipase activity was measured using radioisotope method. Microsomal triglyceride transfer protein activity was measured in the liver and intestine. Plasma apolipoproteinB48, -B100 and apolipoprotein E was measured using Western blots. Two-way ANOVA was used to determine the effect of diet type and animal strain.

Results: The fish oil fed F1B hamsters showed milky plasma after a 14-hour fast. Fish oil feeding caused accumulation of apolipoproteinB48 containing lipoprotein particles suggesting hindrance of triglyceride-rich lipoprotein clearance. There was no significant effect of diet or strain on hepatic or intestinal microsomal triglyceride transfer protein activity indicating that hyperlipidaemia is not due to an increase in the assembly or secretion of lipoprotein particles. F1B hamsters showed significantly reduced levels of lipoprotein lipase activity, which was inhibited by fish oil feeding.

Conclusion: Evidence is presented for the first time that alterations in lipoprotein lipase activity and mRNA levels contribute to varied response of these hamsters to dietary fat, highlighting the importance of genetic background in the regulation of lipid and lipoprotein metabolism by dietary fats. Bio F1B hamster may prove to be an important animal model to investigate nutrient mediated regulation of metabolic parameters under lipoprotein lipase deficiency.

No MeSH data available.


Related in: MedlinePlus