[The growth pattern of atherosclerotic rabbit aortic smooth muscle cells in culture]

Rabbit aortic smooth muscle cells (SMCs) both from normal and atherosclerotic (AS) animals were cultured for study on their growth activities and the relation to the cell cycle kinetics. The growth activities of different cell populations were compared by measuring cell doubling time, labelling index and mitosis index. For cell cycle analysis, 3H-TdR flash labelling method was employed. The results showed that SMCs derived from atherosclerotic rabbits grew more rapidly in culture than those from normal animals, the cell doubling time in the AS group was shorter than normal, 28.8 hrs versus 40.8 hrs, while the labelling and mitosis index in the AS group were higher. SMC cell cycle analysis showed that their generation time was 9.6-9.9 hrs and there was no significant difference of the distribution of cell cycle phases and their generation time between SMCs from AS and control group. The results indicate that the increased proliferative activities of atherosclerotic SMCs are not due to the change of their cell cycle kinetics, but having more cells emerging from G0/G1 phase into S phase.