title: Spironolactone lowers portal hypertension by inhibiting liver fibrosis, ROCK-2 activity and activating NO/PKG pathway in the bile-duct-ligated rat.
abstract: OBJECTIVE
  Aldosterone, one of the main peptides in renin angiotensin aldosterone system (RAAS), has been suggested to mediate liver fibrosis and portal hypertension. Spironolactone, an aldosterone antagonist, has beneficial effect on hyperdynamic circulation in clinical practice. However, the mechanisms remain unclear. The present study aimed to investigate the role of spionolactone on liver cirrhosis and portal hypertension.
  
  
  METHODS
  Liver cirrhosis was induced by bile duct ligation (BDL). Spironolactone was administered orally (20 mg/kg/d) after bile duct ligation was performed. Liver fibrosis was assessed by histology, Masson's trichrome staining, and the measurement of hydroxyproline and type I collagen content. The activation of HSC was determined by analysis of alpha smooth muscle actin (α-SMA) expression. Protein expressions and protein phosphorylation were determined by immunohistochemical staining and Western blot analysis, Messenger RNA levels by quantitative real time polymerase chain reaction (Q-PCR). Portal pressure and intrahepatic resistance were examined in vivo.
  
  
  RESULTS
  Treatment with spironolactone significantly lowered portal pressure. This was associated with attenuation of liver fibrosis, intrahepatic resistance and inhibition of HSC activation. In BDL rat liver, spironolactone suppressed up-regulation of proinflammatory cytokines (TNFα and IL-6). Additionally, spironolactone significantly decreased ROCK-2 activity without affecting expression of RhoA and Ras. Moreover, spironolactone markedly increased the levels of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS and the activity of NO effector-protein kinase G (PKG) in the liver.
  
  
  CONCLUSIONS
  Spironolactone lowers portal hypertension by improvement of liver fibrosis and inhibition of intrahepatic vasoconstriction via down-regulating ROCK-2 activity and activating NO/PKG pathway. Thus, early spironolactone therapy might be the optional therapy in cirrhosis and portal hypertension.
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Southern Medical University, Nanfang Hospital, Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Ying
authors.initials: Y
authors.lastname: Meng
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Ji
authors.forename: Chun-Qiu
authors.initials: CQ
authors.lastname: Pan
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.forename: Chang-Hui
authors.initials: CH
authors.lastname: Yu
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Xiao
authors.forename: Kai
authors.initials: K
authors.lastname: Cui
authors.forename: Shu-Yuan
authors.initials: SY
authors.lastname: Ni
authors.forename: Zhen-Shu
authors.initials: ZS
authors.lastname: Zhang
authors.forename: Xu
authors.initials: X
authors.lastname: Li
mesh_terms: D000199:Actins / Q000378:metabolism; D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000473:pathology*; D008297:Male; D000451:Mineralocorticoid Receptor Antagonists / Q000494:pharmacology; D009130:Muscle, Smooth / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D017082:Portal Pressure; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D013148:Spironolactone / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D000199:Actins; D000451:Mineralocorticoid Receptor Antagonists; D013148:Spironolactone; D009569:Nitric Oxide; D000450:Aldosterone; D054460:rho-Associated Kinases; D017869:Cyclic GMP-Dependent Protein Kinases