Cholesterol Ester Deposition is Reduced in Rats with Hypercholesterolemia and Hypertension

Abstract

High K diets prevent hypertensive endothelial injury and intimal thickening. Cholesterol esters often deposit during hypercholesterolemia. We investigated whether a high K diet would influence cholesterol ester deposits in stroke prone SHR rats. Stroke prone SHR rats were fed for 3 months a basic diet containing 4% cholesterol, 14% coconut oil and 7% NaCl. One group of 13 rats had normal (.5%) K in the diet. Another group of 10 rats ate high (2.1%) K. Mean intraarterial BPs averaged 165 mmHg in the normal K group and 161 mmHg in the high K group (NS). The serum choleserol averaged 229 mg/dl in the the normal K group and 214 in the high K group (NS). Total aortic cholesterol esters per rat averaged 187 μg in normal K vs 68 μg in high K, measured by gas chromatography. Thus high K reduced cholesterol ester deposits by 64% (p<.0003), even though BPs and cholesterol levels were quite similar in the two groupps. Both high cholesterol and high BP injure endothelial cells and increase invasion of monocytes and vascular smooth muscle cells into the intima and increse endothelial permeability to proteins. With high plasma cholesterol, these processes lead to atherosclearosis with cholesterol ester deposition. The high K diet, by protecting endothelial cells, can greatly decrease this choleserol estr deposition. This effect could possibly be useful for preventing heart attacks in human hypertension.

Key Words:

• Hypertension
• Hypercholesterolemia
• Atherosclerosis
• Cholesterol esters
• Dietary potassium