title: Thalidomide effect in endothelial cell of acute radiation proctitis.
abstract: OBJECTIVE
  To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats.
  
  
  METHODS
  Fourteen female Wistar rats were used: six in the radiation group, six in the thalidomide group, and two in normal controls. The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure. The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation. All animals were sacrificed and the rectums were removed on day 8 after irradiation. The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM), von Willebrand Factor (vWF), and vascular endothelial growth factor (VEGF).
  
  
  RESULTS
  The microscopic scores did not differ significantly between the radiation and thalidomide groups, but both were higher than in the control group. Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P<0.001). The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3+/-6.8) than in the control group (3.7+/-1.7), and the number of capillaries expressing vWF was attenuated by thalidomide (10.8+/-3.5, P<0.001). The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P=0.003).
  
  
  CONCLUSIONS
  The mechanisms of acute radiation-induced proctitis in the rats are related to endothelial cell injury of microvessel, which may be attenuated with thalidomide.
authors: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Uijeongbu St. Mary's Hospital, 65-1 Geumo-dong, Uijeongbu city, Kyunggido 480-717, South Korea. chs@catholic.ac.kr
authors: Ki-Tae
authors: KT
authors: Kim
authors: Hiun-Suk
authors: HS
authors: Chae
authors: Jin-Soo
authors: JS
authors: Kim
authors: Hyung-Keun
authors: HK
authors: Kim
authors: Young-Seok
authors: YS
authors: Cho
authors: Whang
authors: W
authors: Choi
authors: Kyu-Yong
authors: KY
authors: Choi
authors: Sang-Young
authors: SY
authors: Rho
authors: Suk-Jin
authors: SJ
authors: Kang
mesh_terms: D000818:Animals; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D005260:Female; D008833:Microcirculation / Q000187:drug effects; D011349:Proctitis / Q000473:pathology / Q000517:prevention & control*; D011833:Radiation Injuries, Experimental / Q000473:pathology / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012007:Rectum / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D013792:Thalidomide / Q000494:pharmacology*; D018180:Thrombomodulin / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D011837:Radiation-Protective Agents; D018180:Thrombomodulin; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D014841:von Willebrand Factor; D013792:Thalidomide