title: Effect of verapamil on nitric oxide synthase in a portal vein-ligated rat model: role of prostaglandin.
abstract: OBJECTIVE
  To investigate the effects of verapamil on nitric oxide (NO) synthesis in a portal vein-ligated rat model.
  
  
  METHODS
  Systemic and splanchnic hemodynamics were measured by radiolabeled microspheres in portal hypertensive rats after acute administration of verapamil (2 mg/kg) on chronic treatment with N(w)-nitro-L-arginine (NNA)(80 mg/kg) and/or indomethacin (2 mg/kg).
  
  
  RESULTS
  Verapamil (2 mg/kg) caused a marked fall in both arterial pressure and cardiac output accompanied by an insignificant change in the portal pressure and no change in portal venous inflow. This result suggested that verapamil did not cause a reduction in portal vascular resistance of portal hypertensive rats, which was similar between N(w)- nitro-L-arginine-treated and indomethacin-treated groups.
  
  
  CONCLUSIONS
  In portal hypertensive rats pretreated with NNA and/or indomethacin, acute verapamil administration can not reduce the portal pressure, suggesting that NO and prostaglandin play an important role in the pathogenesis of splanchnic arterial vasodilation in portal hypertension.
authors: Division of Hepatology and Gastroenterology, Department of Internal Medicine, China Medical University Hospital, No.2, Yuh-Der Road, Taichung 404 Taiwan, China. laycs000@yahoo.com
authors: Chii-Shyan
authors: CS
authors: Lay
authors: C-M-Y
authors: CM
authors: May
authors: Fa-Yauh
authors: FY
authors: Lee
authors: Yang-Te
authors: YT
authors: Tsai
authors: Shou-Dong
authors: SD
authors: Lee
authors: Shu
authors: S
authors: Chien
authors: Shlomoh
authors: S
authors: Sinchon