Is Smooth Muscle Cell Replication a Sensible Target in Human Restenosis?
Smooth muscle cell migration and division doubtlessly contribute importantly to intimal thickening following injury to a previously normal artery. However, abnormal arteries, already exhibiting a complex intimal lesion, represent the substrate for arterial interventional therapy in humans.15 Evidence for ongoing smooth muscle cell division in these arteries is relatively weak. Pickering et al16 showed relatively high indices of proliferation in specimens of human restenotic lesions retrieved by atherectomy. They assessed cell division by expression of the proliferating cell nuclear antigens (PCNA). The sample specimens studied by Pickering et al included many specimens obtained from restenotic peripheral vessels. The study of O’Brien et al,17 using a larger number of restenotic coronary artery atherectomy specimens, showed negligible evidence for smooth muscle cell proliferation in the vast majority of cases. These investigators also presented substantive controls indicating the specif
