OBJECTIVETo observe the developing changes of adventitia in restenosis after precutaneous transluminal angioplasty(PTA), and investigate the effect of androgen on restenosis through contrasting the castrated male rat models and its mechanism.

METHODSModels were constructed of castrated male rats and restenosis of the common carotid artery, and specimens were collected at the 3rd, 7th, 14th and 28th day respectively after modeling. Hematoxylin and eosin staining, immunohistochemical staining, and electronic microscopy were performed to observe the condition of restenosis.

RESULTSProliferating cells occurred in adventitia first and phenotype of adventitial cells was changed at the 3rd day after PTA. The adventitial proliferating index was the highest at the 7th day after PTA, and proliferating migration towards intimal was observed. The proliferating cells mostly occurred in the middle layer and neointima at the 14th day after PTA. The areas of adventitia and neointima were larger and the degrees of restenosis were higher in the castrated rats than in the non-castrated ones at different time points. Take the 14 d group, the adventitial area was[(3,566 +/- 337) micron2 vs (2,751 +/- 401) micron2, P = 0.008], the neointimal area[(3,553 +/- 477) micron2 vs (2,757 +/- 435) micron2, P = 0.025], the restenosis rate[(76 +/- 2)% vs (60 +/- 8)%, P = 0.005], and the proliferating index [(29 +/- 2)% vs (13 +/- 1)%, P < 0.001].

CONCLUSIONAdventitial proliferation and migration contribute to restenosis after PTA; Androgen in rats can physiologically relieve restenosis, probably through intervening in the activation of adventitia.