Hydrophobic surfactant treatment prevents atherosclerosis in the rabbit

The hypocholesterolemic effect of the hydrophobic surfactant, poloxalene 2930, was studied in the rabbit to determine whether this agent prevents experimentally produced atherosclerosis. Male rabbits were divided into four groups and fed a control diet (group A) or an atherogenic diet (groups B, C, and D) for 10 wk. Diets of groups C and D were supplemented with 0.5 and 1% poloxalene 2930, respectively. Animals in group B developed significantly greater levels of cholesterol in the serum and aorta compared with group A. Addition of poloxalene 2930 to the diets of groups C and D prevented significant elevations in cholesterol concentrations of both serum and aorta compared with group B with values for group D being essentially similar to those observed in group A. Groups C and D also had significant increases of fecal excretion of both neutral fat and neutral steroids as compared with either groups A or B. There were no atherosclerotic lesions of the aortas from group D. Aortas from rabbits in group B had numerous atheromatous plaques while one rabbit each from groups A and C had several very small atheromatous lesions. These results demonstrate that poloxalene 2930 reduces the rise of serum cholesterol in rabbits in response to an atherogenic diet and prevents the development of atherosclerosis. This hypocholesterolemic effect is likely mediated by the effect of this surfactant on the small intestine.