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

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.

Effect of propranolol on the splanchnic and peripheral renin angiotensin system in cirrhotic patients

AIM:To evaluate the effect of β-blockade on angiotensins in the splanchnic and peripheral circulation of cirrhotic patients and also to compare hemodynamic parameters during liver transplantation according to propranolol pre-treatment or not. METHODS:Patients were allocated into two groups:outpatients with advanced liver disease(LD) and during liver transplantation(LT). Both groups were subdivided according to treatment with propranolol or not. Plasma was collected through peripheral venipuncture to determine plasma renin activity(PRA),Angiotensin(Ang) Ⅰ,Ang Ⅱ,and Ang-(1-7) levels by radioimmunoassay in LD group. During liver transplantation,hemodynamic parameters were determined and blood samples were obtained from the portal vein to measure renin angiotensin system(RAS) components.RESULTS:PRA,Ang Ⅰ,Ang Ⅱ and Ang-(1-7) were signifi cantly lower in the portal vein and periphery in all subgroups treated with propranolol as compared to non-treated. The relationships between Ang-(1-7) and Ang Ⅰ levels and between Ang Ⅱ and Ang Ⅰ were significantly increased in LD group receiving propranolol. The ratio between Ang-(1-7) and Ang Ⅱ remained unchanged in splanchnic and peripheral circulation in patients under β-blockade,whereas the relationship between Ang Ⅱ and Ang Ⅰ was significantly increased in splanchnic circulation of LT patients treated with propranolol. During liver transplantation,cardiac output and index as well systemic vascular resistance and index were reduced in propranolol-treated subgroup. CONCLUSION:In LD group,propranolol treatment reduced RAS mediators,but did not change the ratio between Ang-(1-7) and Ang Ⅱ in splanchnic and peripheral circulation. Furthermore,the modification of hemodynamic parameters in propranolol treated patients was not associated with changes in the angiotensin ratio.