CELL BIOLOGY OF RESTENOSIS POSTANGIOPLASTY

PTCA is a well established intervention to reduce the severity of athe rosclerotic coronary stenosis. In spite of a primary success rate of 9 0-95 %, late restenosis occurs in 30-50 % of patients within 3/6 month s of the procedure. Angioplasty in swine induces similar events to tho se found in humans, thus providing a model for studying strategies for intervention. Blood interaction to the damaged vessel wall occurs wit h reperfusion after the intervention. There fore, the in vivo characte rization of the interaction of cellular elements (platelets and white cells) and blood proteins with the exposed vascular cells in the vesse l wall post-angioplasty may be necessary to identify early triggers of restenosis. Angioplasty was performed simultaneously in the coronary and carotid arteries of swine by fluoroscopy assisted standard techniq ues. Angiography was performed acutely post-dilatation and residual lu men diameter evaluated. Dilated vessels from 30 min to 6 h postinterve ntion were processed to prepare RNA and preserved to perform immunohis tochemistry. Dilatation injury induces maximal expression of c-fos 30 min and c-myc from 2 to 4 h postdilatation. Platelet deposition is ini tiated immediately post-dilatation as well as infiltration of fluid ph ase proteins on the damaged areas.