Relationship between angiotensin-(1-7) and angiotensin II correlates with hemodynamic changes in human liver cirrhosis.
OBJECTIVE
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).


CONCLUSIONS
Our findings suggest that the relationship between Ang-(1-7) and Ang II may play a role in the hemodynamic changes of human cirrhosis.
Vilas-Boas
Walkíria Wingester
WW
Department of Physiology, Laboratory of Hypertension, Biological Sciences institute, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Ribeiro-Oliveira
Antônio
A
Pereira
Regina Maria
RM
Ribeiro
Renata da Cunha
Rda C
Almeida
Jerusa
J
Nadu
Ana Paula
AP
Simões e Silva
Ana Cristina
AC
dos Santos
Robson Augusto Souza
RA
D000803:Angiotensin I / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D000818:Animals; D003430:Cross-Sectional Studies; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood* / Q000601:surgery; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D012084:Renin-Angiotensin System / Q000502:physiology; D013152:Splanchnic Circulation / Q000502:physiology
D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)