Uptake of acetyl low density lipoprotein (LDL) by stimulated canine macrophages

Canine monocytes from peripheral blood were stimulated by acetyl low density lipoprotein (LDL) to detect receptor-mediated uptake of lipoproteins and to clarify the role of monocytes involving in atherosclerotic lesions. Monocytes collected from peripheral blood which were treated with phorbol 12-myristate 13-acetate (PMA) took up acetyl LDL and differentiated into macrophage-like cells (foamy macrophages). Uptake of acetyl LDL was inhibited specifically by maleyl canine serum albumin (MSA) depending on its concentration. Monocytes treated with PMA did not take up native LDL. These results suggest that canine monocytes express the receptor-mediated uptake of acetyl LDL by a specific pathway (the so-called scavenger receptor) and that they play a crucial role at the initial stage of canine atherosclerotic lesions.