Relationship between expression of type III collagen and phenotype of vascular smooth muscle cells in neointimal of stented coronary artery.
OBJECTIVE
To investigate the secretive features of type III collagen in restenosis of the stented coronary artery and the relationship between the expression of type III. collagen and vascular smooth muscle cells (VSMCs).


METHODS
An animal model of restenosis was established by implanting oversized tantalum stents into the coronary arteries in 26 dogs. At the 7th, 14th and 28th days after implantation, the stented coronaries were harvested. Transmission electronic microscopy and immunohistochemistry were employed to investigate the features of type III collagen secretion and VSMCs' phenotype. The expression of type III collagen was quantified and compared for the three stages.


RESULTS
Migration and proliferation of VSMCs were the main features at the 7th day after injury. At the 14th day, proliferation of VSMCs reached the peak while much more secretion of collagen was noticeable. VSMCs began to transform from the synthetic phenotype to the contractile phenotype at the 28th day, when a great quantity of collagen was also secreted. The quantity of secreted type III collagen was greater at the 14th and 28th day than that at the 7th day (P < 0.05). The stain density of type III collagen was positively correlated to neointimal thickness at both of 14th and 28th day.


CONCLUSIONS
The pathological bases of restenosis are variant in different period of restenosis formation. Type III collagen may play an important role in the late stage of restenosis after coronary stenting.
Xiang
D
D
Department of Cardiology, General Hospital of Guangzhou Command, Guangzhou 510010, China.
Huang
D
D
Gai
L
L
Liu
H
H
D000818:Animals; D002455:Cell Division; D024061:Collagen Type III / Q000032:analysis* / Q000502:physiology; D023903:Coronary Restenosis / Q000209:etiology*; D003331:Coronary Vessels / Q000737:chemistry* / Q000648:ultrastructure; D004285:Dogs; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009131:Muscle, Smooth, Vascular / Q000737:chemistry* / Q000648:ultrastructure; D010641:Phenotype; D015607:Stents
D024061:Collagen Type III