title: Inhibition of nitric oxide synthase in hyperdynamic circulation of rats with early or late cirrhosis secondary to common bile duct ligation.
abstract: OBJECTIVE
  Preventing internal hemorrhage extends the lifespan of rats with chronic bile duct ligation (CBDL), a common animal model of portal hypertension. We investigated hemodynamics during the early and late stages of cirrhosis caused by CBDL. We also evaluated the hemodynamic influence of NO, which is the chief vasodilator in hyperdynamic syndrome, by administration of an NO synthase inhibitor (N(G)-nitro-L-arginine methyl ester: L-NAME; 10 mg/kg). ANIMALS/METHODS: In 24 Sprague-Dawley rats (9 sham rats and 15 CBDL rats), hemodynamics were assessed under conscious and unrestrained conditions 4 and 8 weeks after surgery. Before and 30 minutes after L-NAME administration, the cardiac index (CI) and regional blood flow were measured with the reference sample method using (141)Ce- and (113)Sn-microspheres (15 µm in diameter).
  
  
  RESULTS
  A hyperdynamic systemic circulation and splanchnic hyperemia were observed after CBDL, and these changes increased with the progression of cirrhosis. L-NAME significantly diminished the hyperdynamic circulation and also reduced splanchnic hyperemia. In 4-week CBDL rats, a low hemoglobin concentration made an important contribution to the hyperdynamic circulation, and the portal collateral system collapsed when inflow to the portal territory was reduced by L-NAME treatment. In 8-week CBDL rats, systemic hemodynamics were closely linked to both the splanchnic circulation and the renal circulation before and after L-NAME administration, apart from hepatic artery blood flow.
  
  
  CONCLUSIONS
  The distinctive hemodynamic changes of portal hypertension were found in 8-week CBDL rats. Thus, 8-week CBDL rats may be a better animal model of human portal hypertension than 4-week CBDL rats.
authors: Divisions of Cardiology, Hepatology, Geriatrics, and Integrated Medicine, Department of Internal Medicine, Graduate School of Medicine, Nippon Medical School.
authors: Yoshihito
authors: Y
authors: Kato
authors: Yasumi
authors: Y
authors: Katsuta
authors: Xue-Jun
authors: XJ
authors: Zhang
authors: Masaru
authors: M
authors: Ohsuga
authors: Toshio
authors: T
authors: Akimoto
authors: Akiko
authors: A
authors: Miyamoto
authors: Hirokazu
authors: H
authors: Komeichi
authors: Shuji
authors: S
authors: Shimizu
authors: Kyoichi
authors: K
authors: Mizuno
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003135:Common Bile Duct / Q000187:drug effects / Q000473:pathology*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008026:Ligation; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008102:Liver Circulation / Q000187:drug effects / Q000502:physiology*; D008103:Liver Cirrhosis / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D017082:Portal Pressure / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester