PROLIFERATIVE EFFECTS OF OXIDIZED LOW-DENSITY-LIPOPROTEIN ON VASCULARSMOOTH-MUSCLE CELLS - ROLE OF DIETARY HABITS

The effects were studied of native, partially-oxidized and totally-oxi dized human low-density lipoprotein (LDL) on the proliferation of cult ured rat aortic smooth muscle cells (VSMC), measured as an altered DNA synthesis. The LDL was obtained from three different human long-term diet groups (a control diet rich in saturated fats, a vegetarian diet, and a fish diet). The oxidized LDLs were prepared by oxidizing the LD L with copper sulfate. The DNA synthesis was measured by [H-3]-thymidi ne incorporation into the DNA. The partially-oxidized LDL was the most potent promoter of DNA synthesis compared to the native or totally-ox idized LDL of the same diet group. The partially-oxidized LDL had a tr ue mitogenic effect in the absence of exogenous growth factors. The na tive and totally-oxidized LDL induced a significant increase in DNA sy nthesis, if they were obtained from the fish diet group. This study su ggests an enhanced proliferative effect of partially-oxidized LDL on V SMC growth.