Dietary linoleic acid‐induced hypercholesterolemia and accumulation of very light HDL in steers

Abstract

This experiment was designed to study the effects in fattening steers of n-6 PUFA supplementation on the plasma distribution and chemical composition of major lipoproteins (TG-rich lipoproteins: d < 1.006 g/mL; intermediate density lipoproteins + LDL: 1.019 < d < 1.060 g/mL; light HDL: 1.060 < d < 1.091 g/mL; and heavy HDL: 1.091 < d < 1.180 g/mL). For a period of 70 d, animals [454 +/- 20 d; 528 +/- 36 kg (mean +/- SD)] were given a control diet (diet C, n = 6) consisting of hay and concentrate mixture (54 and 46% of diet dry matter, respectively) or the same diet supplemented with sunflower oil (4% of dry matter), given either as crushed seeds (diet S, n = 6) or as free oil continuously infused into the duodenum through a chronic canula to avoid ruminal PUFA hydrogenation (diet O, n = 6). Plasma lipids increased in steers given diet S (x1.4, P < 0.05) and diet O (x2.3, P < 0.05), leading to hyperphospholipemia and hypercholesterolemia. With diet S, hypercholesterolemia was associated with higher levels of light (x1.4, P < 0.05) and heavy HDL (x1.3, NS). With diet O, it was linked to higher levels of light HDL (x1.8, P < 0.005) and to very light HDL accumulation within density limits of 1.019 to 1.060 g/mL, as demonstrated by the apolipoprotein A-I profile. Diet O favored incorporation of 18:2n-6 into polar (x2.2, P < 0.05) and neutral lipids (x1.5 to x8, P < 0.05) at the expense of SFA, MUFA, and n-3 PUFA. Thus, protection of dietary PUFA against ruminal hydrogenation allowed them to accumulate in plasma lipoproteins, but the effects of hypercholesterolemia on animal health linked to very light HDL accumulation remain to be elucidated.

Transport of fatty acids within plasma lipoproteins in lactating and non‐lactating cows fed on fish oil and hydrogenated palm oil

“…Dietary FA are known to modify lipids and lipoprotein metabolism (Scislowski et al., ). In bovines, HDL is the major plasma lipoprotein fraction (Bauchart, ) which can be notably influenced by dietary PUFA when directly infused into the proximal duodenum (Scislowski et al., ) or when pre‐ruminant calves are supplemented with soya bean oil (Leplaix‐Charlat et al., ) or when dairy cows are fed protected sunflower oilseed (Ashes et al., ) or protected soya bean (Storry et al., ).…”

“…In this study, FO increased total PUFA in plasma of lactating and non‐lactating cows. It has been shown (Scislowski et al., ) that dietary enrichment with PUFA increases lipoprotein fluidity compared with diets rich in SFA, and such changes in the physical state of lipoproteins can interfere with their physiological roles affecting lipoprotein–receptor interactions and thus reverse cholesterol transport (Scislowski et al., ). More research should be performed to study the consequences of long‐term lipid supplementation on lipoprotein profiles.…”

“…It has been demonstrated that alterations in the diet can affect the distribution and chemical composition of plasma lipoproteins in models such as in humans (Blair et al., ), and in animal models such as rabbits (Niimi et al., ), rats (Sawale et al., ), swine (Nichols et al., ) and chickens (Jensen et al., ). Also, it has been shown that the degree of saturation of dietary lipids can affect the chemical composition of plasma lipoproteins in steers (Scislowski et al., ,b) and dairy cows (Offer et al., ).…”

Potential of fluorescence spectroscopy to predict fatty acid composition of beef

“…= 0.25 mm). The carrier gas was H 2 and the oven and flame ionization detector temperatures described by Scislowski, Durand, Gruffat, and Bauchart (2004) were used. Total FAs were quantified using C19:0 as an internal standard.…”

Effect of dietary supply of butters rich either in trans-10-18:1 or in trans-11-18:1 plus cis-9, trans-11-18:2 on rabbit adipose tissue and liver lipogenic activities

“…The fatty acid present in these samples were methylated at room temperature by the BF 3 -sodium methanolate method (Sébédio et al 1999), and subsequently analysed by GLC using a DI 200 chromatograph (Perichrom, Saulx-les-Chartreux, France) equipped with a CP-Sil 88 glass capillary column (length 100 m, internal diameter 0•25 mm). Conditions for GLC analysis have been described previously (Scislowski et al 2004). The oven temperature was held constant for 30 s at 708C, then increased from 70 to 1758C at 208C/min, held at 1758C for 25 min, increased again from 175 to 2158C at 108C/ min, and was finally held at 2158C for 41 min.…”