Interactive effects of increased intake of saturated fat and cholesterol on atherosclerosis in the Japanese quail (Coturnix japonica)

Abstract

Increasing the energy value of diets with dietary fat, particularly fats rich in saturated fatty acids, can result in the elevation of plasma total and lipoprotein cholesterol. In the present study, experimental diets were designed to examine the effects of increasing the energy content of diets with a saturated fat source and cholesterol in a non-purified diet on hyperlipoproteinaemia and aortic plaque composition in the atherosclerosis-susceptible Japanese quail (Coturnix japonica) model of human atherosclerosis. Commercial poultry diets containing two levels (i.e. 60 or 120 g/ kg) of beef tallow as the primary source of saturated fat were balanced for endogenous cholesterol or supplemented with cholesterol (i.e. 0 . 5 or 5 . 0 g/kg) and fed to quail for 9 weeks to examine the effects on whole plasma, lipoprotein and aortic plaque lipid composition in relation to aortic plaque formation. Hypercholesterolaemia (P Ͻ 0 . 001) was confirmed in birds fed on highcholesterol (HC) diets only. An interaction (P ¼ 0 . 05) between dietary cholesterol and fat intake level was observed for plasma triacylglycerols (TG) and was specific to changes observed in VLDL composition. Diet-induced changes in lipoprotein total cholesterol, TG and phospholipid composition were greatest in the portomicron and VLDL fractions in birds fed on atherogenic diets. Hyperlipoproteinaemia induced by the 60 g/kg added beef tallow-HC diet resulted in significant (P Ͻ 0 . 001) aortic plaque deposition, which was further enhanced in birds fed on the 120 g/kg beef tallow-HC diet. Quail fed on 120 g/kg beef tallow-HC diets exhibited the most severe aortic plaque formation, with marked increases in aortic tissue cholesterol content and quantifiable amounts of several cholesterol oxides (5,6a-epoxy-5a-cholesterol, 7b-hydroxycholesterol, cholestanetriol, 7-ketocholesterol and 25-hydroxycholesterol). In summary, hyperlipoproteinaemia associated with HC diets with a greater proportion of energy from saturated fat produced a combined effect in altering plasma and lipoprotein lipid composition as well as aortic tissue cholesterol and cholesterol oxide content in the Japanese quail.Atherosclerosis: Japanese quail: Lipoproteins: Cholesterol

Effects of artificial foods on the blood chemistry of the Australian magpie

“…Plasma cholesterol is one blood lipid fraction (Bell & Sturkie 1965) and captive and free-ranging studies have reported that birds fed with dietary cholesterol show significantly increased the PC levels (Gavett & Wakeley 1986;Yuan et al 1997Yuan et al , 1998Eder 1999).…”

“…For example, a cholesterol-rich diet facilitated the development of atherosclerotic plaque in Japanese quail (Coturnix japonica) (Yuan et al 1997(Yuan et al , 1998 and increased the concentrations of cholesterol in the liver (Eder 1999 in cross-bred geese; Yuan et al 1999 in Japanese quail). There is a possibility of similar effects among fed magpies if the influence of feeding at plasma level that we demonstrated in this experiment can be generalized to a wider scale.…”

Antioxidant Supplements Improve Profiles of Hepatic Oxysterols and Plasma Lipids in Butter-fed Hamsters

“…Similar to the enzymatically generated oxysterols that are associated with diets high in cholesterol,41–43 free radical generated oxysterols are produced via consumption of HCHS diets;44 however, they do not act as ligands for LXR. Moreover, recent evidence suggests that free radical generated oxysterols can impede the physiological actions of enzymatic oxysterols 45.…”

Clinicochemical follow-up of broiler rearing — A five-week study

“…It is known that increasing the ingestion of dietary fat or its saturated fatty acid proportion can induce higher plasma cholesterol levels without largely influencing plasma TG concentrations (Feoli et al, 2003). Thus, it may be the dietary fatty acid profile (Table 1), primarily the level of unsaturation (as shown by the unsaturation index) that had a lowering effect on the total cholesterol level, as also demonstrated in quails (Yuan et al, 1998), chicks (Feoli et al, 2003) and rabbits (Szabó et al, 2004). Interestingly, the change from yolk to feed was matched by a marked increase in the unsaturation of the dietary fatty acid profile.…”