Vitamin A and its derivatives (retinoids) are capable of inhibiting vascula
r smooth muscle cell proliferation in vitro. The present study examines the
effect of two retinoids, all-trans retinoic acid and 13-cis retinoic acid,
on intimal hyperplasia following arterial injury. After receiving varying
doses of all-trans retinoic acid or 13-cis retinoic acid, 78 male Sprague-D
awley rats underwent standard balloon catheter denudation of the left commo
n carotid artery. Morphometric analysis and immunohistochemistry for prolif
erating cell nuclear antigen was performed at early and late time points. I
ntimal/medial ratios were reduced in a dose-dependent fashion for animals t
reated with all-trans retinoic acid (P = 0.001) and 13-cis retinoic acid (P
= 0.004). Proliferating eel nuclear antigen labeling indices were reduced
after treatment with all-trans retinoic acid and 13-cis retinoic acid at ea
rly time points post-injury. At a dose of 10 mg/kg, both all-trans retinoic
acid and 13-cis retinoic acid inhibited vessel remodeling as measured by i
ncreases in luminal diameter (P < 0.05) and external elastic lamina (P < 0.
05). Retinoids are an attractive clinical option for the treatment of reste
nosis following angioplasty and arterial surgery. (C) 1999 The Internationa
l Society for Cardiovascular Surgery, Published by Elsevier Science Ltd. Al
l rights reserved.