Modulation of the regression of atherosclerosis in the hamster by dietary lipids: comparison of coconut oil and olive oil

Abstract

The Golden Syrian hamster (Mesocricetus auratus) has been shown to be a useful model of both human lipoprotein metabolism and the development of atherosclerosis. We report the effects of dietary lipids on the progression and regression of atherosclerosis in this model. In the first study, hamsters fed on coconut oil (150 g/kg diet) and cholesterol (30 g/kg diet) developed lipid-rich lesions in the ascending aorta (0⋅28 (SD 0⋅14) mm 2 ) and aortic arch (0⋅01 (SD 0⋅01) mm 2 ) after 4 weeks that continued to progress over the next 8 weeks (0⋅75 (SD 0⋅41) mm 2 and 0⋅12 (SD 0⋅11) mm 2 for the ascending aorta and aortic arch respectively). Removal of cholesterol from the diet halted this progression. Furthermore, in animals fed on olive oil in the absence of added cholesterol, plasma LDL-cholesterol concentrations were lower (P Ͻ 0⋅05) and the extent of atherosclerotic lesions was reduced (P Ͻ 0⋅001 for both regions of the aorta) compared with animals fed on coconut oil (with no added cholesterol). In a second study, animals were fed on the atherogenic diet for 10 weeks, transferred to diets containing either coconut oil (150 g/kg diet) or olive oil (150 g/kg diet) without added cholesterol and monitored for up to 16 weeks. In the ascending aorta, lesion size doubled in animals fed on coconut oil but stabilized in those fed on olive oil. In the aortic arch, lesion size decreased linearly (P Ͻ 0⋅05, P Ͻ 0⋅001 for coconut oil and olive oil respectively) with the greatest reduction being seen in the olive-oil-fed animals (P Ͻ 0⋅05). Again, progression and regression of atherosclerosis appeared to reflect the relative concentrations of LDL-cholesterol and HDL-cholesterol in the plasma. We conclude that the male Golden Syrian hamster represents a useful model of dietary induced regression as well as progression of atherosclerosis. Hamster: Atherosclerosis: Coconut oil: Olive oil: Dietary fatThe Golden Syrian hamster (Mesocricetus auratus) has been used extensively in studies of lipoprotein metabolism.

Butters rich either in trans-10-C18:1 or in trans-11-C18:1 plus cis-9, trans-11 CLA differentially affect plasma lipids and aortic fatty streak in experimental atherosclerosis in rabbits

“…The positive close relationship between the triglyceridemia and the severity of lipid deposition in the aorta of rabbits was already reported in hamsters (Mangiapane et al, 1999) and is in accordance with the fact that hypertriglyceridemia is an independent risk factor of atherosclerosis in human (Hennig et al, 2001).…”

Does Therapeutic Intervention Achieve Slowing of Progression or Bona Fide Regression of Atherosclerotic Lesions?

“…28 The regression of fatty streaks was also found in another study 29 with a low-fat, low-cholesterol diet with or without supplementation of lovastatin. In a recent study, 30 the effect of coconut oil versus olive oil on regression of lesions in the ascending aorta and aortic arch was compared after 8 or 16 weeks. In the ascending aorta, coconut oil increased the extent of lesions, whereas with olive oil, no regression occurred up to 16 weeks.…”

“…Different results were reported for aortic arch, in which both coconut oil and especially olive oil enhanced regression. 30 …”

Dietary cholesterol reduces lipoprotein lipase activity in the atherosclerosis-susceptible Bio F1B hamster

“…It has also proven to be a useful model in studying pharmacological (Kowala et al 1991(Kowala et al , 1993Foxall et al 1992;Otto et al 1995;Nicolosi et al 1998a;Pitman et al 1998) and nutritional influences on the development of atherosclerosis (Parker et al 1995;Kahlon et al 1996;Nicolosi et al 1997Nicolosi et al , 1998bXu et al 1998;Mangiapane et al 1999). Previous studies in our laboratory (Mangiapane et al 1999) showed that one strain of hamster (dominant spot normal inbred, DSNI) required high levels of dietary cholesterol (30 g/kg diet) to induce aortic lesions. This is in agreement with earlier findings of Nistor et al (1987).…”