Effectiveness of narrow-band ultraviolet-B phototherapy for prevention of intimal hyperplasia in a rat carotid balloon injury model.
OBJECTIVE
Narrow-band ultraviolet-B light (NBUVB) (313 nm) is known to have anti-proliferative effects, implying a potential treatment for intimal hyperplasia, but it remains to be ascertained. We assessed the effects of NBUVB irradiation for prevention of intimal hyperplasia.


METHODS
The rat carotid arteries were irradiated with NBUVB after balloon injury (BI), and the degree of intimal hyperplasia was histopathologically assessed. The anti-proliferative effects using cultured human smooth muscle cells were evaluated by flow cytometry and immunoblot analysis.


RESULTS
NBUVB (0.3-4.5 J/cm(2)) irradiation immediately after BI reduced the degree of intimal hyperplasia at 14 and 28 days after BI (P<0.001) without any obvious complications. Neither an increase in the number of medial cells nor upregulation of proliferating cell nuclear antigen was observed in the irradiated arteries. NBUVB irradiation at 2 or 14 days after BI significantly suppressed further intimal hyperplasia (P<0.01). NBUVB-irradiated cultured cells showed inhibited proliferation involved with G(1) and G(2)/M arrests. Increased expression of p53 and inhibition of retinoblastoma protein (pRB) phosphorylation were also seen in the NBUVB-irradiated cells.


CONCLUSIONS
These data suggest that NBUVB irradiation is an effective method for preventing intimal hyperplasia. The anti-proliferative effect is partly due to the cell cycle arrest caused by p53 expression and inhibited pRB phosphorylation.
Kohyama
Shinya
S
Department of Radiology, National Defense Medical College, Saitama, Japan 359-8513.
Morimoto
Yuji
Y
Nakai
Kanji
K
Kaji
Tatsumi
T
Tokumaru
Aya
A
Nawashiro
Hiroshi
H
Shima
Katsuji
K
Satoh
Yasushi
Y
Takishima
Kunio
K
Kikuchi
Makoto
M
Matsuo
Hirotaka
H
D000818:Animals; D015153:Blotting, Western; D020212:Carotid Artery Injuries / Q000473:pathology / Q000517:prevention & control*; D017536:Carotid Artery, Common / Q000473:pathology*; D002404:Catheterization; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005434:Flow Cytometry; D006965:Hyperplasia; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017539:Tunica Intima / Q000293:injuries* / Q000473:pathology*; D014467:Ultraviolet Therapy