It is known that high-cholesterol diet impairs coronary vasodilatation in animal models of athe-rosclerosis irrespective of overt pathology. We evaluated the specific role of LDL and HDL on adenosine-elicited coronary vasodilatation after short time (10 weeks) high-cholesterol diet in pigs. Nineteen pigs on standard (C), atherogenic (HF) and alternate standard or atherogenic diet every other week (IHF) underwent left coronary angiography and flow (CFR) measurement during intracoronary adenosine injection. Total cholesterol, HDL, LDL, Apo lipoprotein A-1, IL-6, TNF-α and ICAM-1 were measured and histology of coronary samples was performed. IHF and HF show comparable intimal thickening of lesions, similar cholesterol (598.4 ± 198.2 and 633.2 ± 83.5 mg/dL) and LDL (502.6 ± 193.7 and 576.1 ± 83.2), while HDL is double in IHF group (88.3 ± 6.4 vs 46.4 ± 18.7 p