Lipoprotein inflammatory properties and serum amyloid A levels but not cholesterol levels predict lesion area in cholesterol-fed rabbits

Abstract

Rabbits on a 1% cholesterol diet received injections of vehicle with or without D-4F or L-4F. After 1 month, the percent of aorta with atherosclerotic lesions was 24 ± 15% (vehicle), 10 ± 6% (D-4F) (P < 0.01 vs. vehicle), and 13 ± 9% (L-4F) (P < 0.05 vs. vehicle). Inflammatory indexes for HDL and LDL were determined by measuring monocyte chemotactic activity after adding rabbit lipoproteins to human endothelial cells. HDL-inflammatory index (HII) and LDL-inflammatory index (LII), respectively, were 1.39 ± 0.24; 1.35 ± 0.29 (vehicle), 0.67 ± 0.26; 0.63 ± 0.38 (D-4F) (P < 0.001 vs. vehicle), and 0.67 ± 0.2; 0.68 ± 0.32 (L-4F) (P < 0.01 vs. vehicle). Serum amyloid A (SAA) levels were 95 ± 39, 8 ± 22, and 7 ± 19 μg/ml, respectively, for vehicle, D-4F, and L-4F (P < 0.001 vs. vehicle). There was no correlation between lesion area and total plasma or HDL-cholesterol levels. In contrast, there was a positive correlation with HII, LII, and SAA (P = 0.002, P = 0.0026, P = 0.0079, respectively). HII correlated closely with SAA levels (r = 0.6616; r2 = 0.4377, P < 0.0001). Thus, HII, LII, and SAA are better predictors of lesion area than are total plasma or HDL-cholesterol levels in cholesterol-fed rabbits.

Keywords

• atherosclerosis
• LDL
• HDL
• apolipoprotein A-I mimetic peptides
• inflammation