ASSESSMENT OF MYOINTIMAL CELLULAR KINETICS IN A MODEL OF ANGIOPLASTY BY MEANS OF PROLIFERATING CELL NUCLEAR ANTIGEN EXPRESSION

A detailed temporal assessment of cellular proliferation was carried o ut by means of immunostaining for proliferating cell nuclear antigen i n a normolipemic rabbit model of balloon angioplasty to the iliac arte ries. Assessment was made at 30 minutes, 2 hours, 1 day, 3 days, 7 day s, 14 days, 1 month and 3 months after the procedure. Intimal hyperpla sia was first noted at day 3; a prominent layer was formed by day 14. Cellular proliferation in the vessel media was observed as early as da y 1 (percentage of positive-staining cells 0.5% +/- 0.2%), reaching a maximum by day 7 (16.9% +/- 5.1%) before returning to baseline levels by 1 month (0.2% +/- 0.02%); in the intima, cellular proliferation was first noted at day 7 (0.7% +/- 0.3%) and reached a maximum at day 14 (4.1% +/- 0.4%) before returning to baseline levels at 1 month (0.3% /- 0.1%). Use of proliferating cell nuclear antigen expression in this model of angioplasty provided a simple and reproducible method of ass essing cellular proliferation after vascular injury and may prove usef ul for monitoring the effects, in experimental models, of agents for r educing myointimal hyperplasia.