RESUMEN
AIM: To investigate the relations between the proliferation and phenotype change of adventitial cells and the expression of T GF-?1 in adventitia after arterial injury. METHODS: After abdominal artery injury in rabbits, adventitial cel l proliferation and phenotype were identified by immunohistochemistry, transmissi on electron microscope and in situ Hybridization. RESULTS: Three days and 7 days after injury, the PCNA-positive ce lls were significantly increased. The previously weakly actin-positive adventiti al cells became strong-actin staining, the typical myofibroblast featurses of ad ventitial cells were detected by TEM 7 and 14 days after injury. Three days afte r vascular injury, there was a marked increase in the nu mber of cells that demonstrated the presence of TGF-?1 transcripts within the adventitia. Seven days after arterial injury, adventitial cells continued to ex press TGF-?1. on day 28, the number of TGF-?1-expressing cells was markedly r e duced in the adventitia. CONCLUSION: This study demonstrates that the proliferation and p henotype modulation of adventitial cells are associated with induction of TGF- ?1 expression in adventitia after arterial injury.