Heparin inhibits intimal thickening after @entity1317 . Whether this effect is due to inhibition of medial smooth muscle cell (SMC) migration, SMC proliferation in the intima, or synthesis and deposition of connective tissue has not been evident. In this study we have investigated these possibilities in a @entity35 carotid @entity130 model. Heparin (0.3 mg/kg/hour) was administered intravenously by means of osmotic pumps to experimental animals, and controls received lactated Ringer's solution. Smooth muscle proliferation ( @entity1014 index), intimal smooth muscle accumulation, and endothelial regeneration were measured at intervals between 0 and 28 days. Total smooth muscle growth as determined biochemically at 14 days was markedly inhibited by heparin if the pumps were placed 24 hours before or at the time of injury and less so if inserted 48 or 96 hours after injury. SMC @entity1014 indices were maximal in the media at 4 days and in the intima at 7 days for injured arteries of both heparin-treated and control @entity35 ; at each time point SMC proliferation and intimal thickening were less in heparin-treated @entity35 . The volume of connective tissue in the intima was the same in both groups at 28 days. Medial SMC migration into the intima was diminished by heparin treatment, but endothelial regeneration was not affected. These results support the hypothesis that heparin is a specific inhibitor of SMC migration and proliferation and is most effective if started before SMC enter S-phase.

Kinetics of cellular proliferation after XXXX . II. Inhibition of smooth muscle growth by heparin.

@entity1317 :: ('MESH:D057772', 'Disease') :: ['arterial injury'] @entity1014 :: ('MESH:D013936', 'Chemical') :: ['thymidine'] @entity130 :: ('MESH:D014947', 'Disease') :: ['balloon injury'] @entity35 :: ('10116', 'Species') :: ['rat', 'rats']
@entity1317 :: (MESH:D057772,Disease) :: ['arterial injury']
