Brief Articles
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World J Gastroenterol. May 28, 2009; 15(20): 2512-2519
Published online May 28, 2009. doi: 10.3748/wjg.15.2512
Relationship between angiotensin-(1-7) and angiotensin II correlates with hemodynamic changes in human liver cirrhosis
Walkíria Wingester Vilas-Boas, Antônio Ribeiro-Oliveira Jr, Regina Maria Pereira, Renata da Cunha Ribeiro, Jerusa Almeida, Ana Paula Nadu, Ana Cristina Simões e Silva, Robson Augusto Souza dos Santos
Walkíria Wingester Vilas-Boas, Jerusa Almeida, Ana Paula Nadu, Robson Augusto Souza dos Santos, Laboratory of Hypertension, Department of Physiology, Biological Sciences institute, Federal University of Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil
Antônio Ribeiro-Oliveira Jr, Renata da Cunha Ribeiro, Laboratory of Endocrinology, Department of Medicine, Faculty of Medicine, Federal University of Minas Gerais, Av. Alfredo Balena, 190, Belo Horizonte, MG, 30130-100, Brazil
Regina Maria Pereira, Hospitalar Foundation of the State of Minas Gerais, FHEMIG, Belo Horizonte, MG, Brazil
Ana Cristina Simões e Silva, Department of Pediatrics, Faculty of Medicine, Federal University of Minas Gerais, Av. Alfredo Balena, 190, Belo Horizonte, MG, 30130-100, Brazil
Author contributions: Vilas-Boas WW, Santos RAS designed the study; Vilas-Boas WW, Ribeiro RC, Almeida J, Nadu AP performed the research; Vilas-Boas WW, Ribeiro-Oliveira Jr A, Pereira RM, Simões e Silva AC analyzed the data; Vilas-Boas WW, Ribeiro-Oliveira Jr A, Pereira RM, Simões e Silva AC, Santos RAS wrote the paper.
Correspondence to: Robson Augusto Souza dos Santos, Laboratory of Hypertension, Department of Physiology, Biological Sciences institute, Federal University of Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil. robsonsant@gmail.com
Telephone: +55-31-34992924
Fax: +55-31-34992956
Received: February 13, 2009
Revised: April 23, 2009
Accepted: April 30, 2009
Published online: May 28, 2009
Abstract

AIM: To measure circulating angiotensins at different stages of human cirrhosis and to further evaluate a possible relationship between renin angiotensin system (RAS) components and hemodynamic changes.

METHODS: Patients were allocated into 4 groups: mild-to-moderate liver disease (MLD), advanced liver disease (ALD), patients undergoing liver transplantation, and healthy controls. Blood was collected to determine plasma renin activity (PRA), angiotensin (Ang) I, Ang II, and Ang-(1-7) levels using radioimmunoassays. During liver transplantation, hemodynamic parameters were determined and blood was simultaneously obtained from the portal vein and radial artery in order to measure RAS components.

RESULTS: PRA and angiotensins were elevated in ALD when compared to MLD and controls (P < 0.05). In contrast, Ang II was significantly reduced in MLD. Ang-(1-7)/Ang II ratios were increased in MLD when compared to controls and ALD. During transplantation, Ang II levels were lower and Ang-(1-7)/Ang II ratios were higher in the splanchnic circulation than in the peripheral circulation (0.52 ± 0.08 vs 0.38 ± 0.04, P < 0.02), whereas the peripheral circulating Ang II/Ang I ratio was elevated in comparison to splanchnic levels (0.18 ± 0.02 vs 0.13 ± 0.02, P < 0.04). Ang-(1-7)/Ang II ratios positively correlated with cardiac output (r = 0.66) and negatively correlated with systemic vascular resistance (r = -0.70).

CONCLUSION: Our findings suggest that the relationship between Ang-(1-7) and Ang II may play a role in the hemodynamic changes of human cirrhosis.

Keywords: Renin-angiotensin system; Liver cirrhosis; Angiotensin-(1-7); Angiotensin II; Splanchnic circulation; Angiotensin converting enzyme 2