RABBIT AORTIC SMOOTH-MUSCLE CELL-CULTURE - A MODEL FOR THE PHARMACOLOGICAL STUDY OF DIABETES-INDUCED ALTERATIONS IN CELL-PROLIFERATION

Atherosclerotic vascular disease is the most common complication of diabetes mellitus. Enhanced vascular smooth muscle cell proliferation plays a central role in atherosclerotic lesion formation. Studies using explant cultures have demonstrated that aortic smooth muscle cells from rats with experimental or genetic diabetes have enhanced rates of proliferation when compared to controls. However, this method of culture may select for cells with enhanced migratory potential. In the present studies, aortic smooth muscle cells were successfully cultured from control and diabetic rabbits after enzymatic and mechanical dispersion from thoracic aortic segments. The proliferative patterns of control cells were characterized and growth rates of diabetic cells were compared to controls. Primary cultures from control rabbits grew after an initial 5-day lag period to achieve threefold increases in cell number by 9 days. Subcultures of aortic smooth muscle cells entered the logarithmic phase of growth after 2 days, reaching the plateau phase of growth in 5-7 days and achieving three to fourfold increases in cell number. The final density to which cultures grew was not affected by the number of cells attached on day 1 for the range studied. Cells from diabetic rabbits displayed shorter doubling times and reached greater densities at confluence than did cells from controls. These data support the hypothesis that diabetes induces an atherogenic response. The dissociated rabbit aortic smooth muscle cell culture provides a model in which to study diabetes-induced modulation of cell proliferation that is amenable to pharmacological manipulation to investigate agonist and growth factor-induced responses.