The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can ...The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.展开更多
Background: Hypertension (HTN) is present in up to 90% of end stage kidney disease (ESRD) patients irrespective of the etiology of their kidney disease. Moreover, it is an important modifiable risk factor for progress...Background: Hypertension (HTN) is present in up to 90% of end stage kidney disease (ESRD) patients irrespective of the etiology of their kidney disease. Moreover, it is an important modifiable risk factor for progression to ESRD and its overall cardiovascular morbidity and mortality. Objective: to evaluate, prospectively, the role of Renin-Angiotensin-Aldosterone System blockade (RAAS) in HTN, resistant to 3 conventional antihypertensives, in patients on maintenance hemodialysis (MHD). Patients and methods: A total of 52 such patients were treated with Ramipril and 5 with Losartan after intolerable cough/shortness of breath following Ramipril-use. None of the patients had fluid depletion, renal artery stenosis and primary endocrinopathy. The study group was compared to a matched control group of MHD patients with normal blood pressure following 3 drugs-combination therapies. Results: All patients, with resistant HTN, had significant activation of RAAS system prior to treatment compared to inactive one in the control group. In those with resistant HTN, control of HTN, was established within 2 weeks of therapy and was associated with suppression of the RAAS. Such therapy was associated with minor side effects. Conclusion: Our study has shown that RAAS blockade is safe and effective in controlling such resistant HTN in MHD patients.展开更多
The kallikrein-kinin system(KKS) is an intricate endogenous pathway involved in several physiological and pathological cascades in the brain. Due to the pathological effects of kinins in blood vessels and tissues, the...The kallikrein-kinin system(KKS) is an intricate endogenous pathway involved in several physiological and pathological cascades in the brain. Due to the pathological effects of kinins in blood vessels and tissues, their formation and degradation are tightly controlled. Their components have been related to several central nervous system diseases such as stroke, Alzheimer's disease, Parkinson's disease, multiple sclerosis, epilepsy and others. Bradykinin and its receptors(B1R and B2R) may have a role in the pathophysiology of certain central nervous system diseases. It has been suggested that kinin B1R is up-regulated in pathological conditions and has a neurodegenerative pattern, while kinin B2R is constitutive and can act as a neuroprotective factor in many neurological conditions. The renin angiotensin system(RAS) is an important blood pressure regulator and controls both sodium and water intake. AngⅡ is a potent vasoconstrictor molecule and angiotensin converting enzyme is the major enzyme responsible for its release. AngⅡ acts mainly on the AT1 receptor, with involvement in several systemic and neurological disorders. Brain RAS has been associated with physiological pathways, but is also associated with brain disorders. This review describes topics relating to the involvement of both systems in several forms of brain dysfunction and indicates components of the KKS and RAS that have been used as targets in several pharmacological approaches.展开更多
Available evidence points to a possible role of the renin-angiotensin system(RAS)in the pathophysiology of mood disorders and suicide.We carried out a critical analysis of literature data regarding this role,with a fo...Available evidence points to a possible role of the renin-angiotensin system(RAS)in the pathophysiology of mood disorders and suicide.We carried out a critical analysis of literature data regarding this role,with a focus on the proposed association between RAS dysfunction and suicidal behavior.Epidemiological,genetic,and biochemical findings are described,and the pathophysiological hypothesis aiming at explaining the possible relationship between RAS and suicide are discussed.Available findings do support the involvement of the RAS in the neurobiology of suicide,although the exact mechanisms underlying this involvement are still unknown.展开更多
Several pharmacological agents to prevent the progression of diabetic kidney disease(DKD)have been tested in patients with type 2 diabetes mellitus(T2DM)in the past two decades.With the exception of renin-angiotensin ...Several pharmacological agents to prevent the progression of diabetic kidney disease(DKD)have been tested in patients with type 2 diabetes mellitus(T2DM)in the past two decades.With the exception of renin-angiotensin system blockers that have shown a significant reduction in the progression of DKD in 2001,no other pharmacological agent tested in the past two decades have shown any clinically meaningful result.Recently,the sodium-glucose cotransporter-2 inhibitor(SGLT-2i),canagliflozin,has shown a significant reduction in the composite of hard renal and cardiovascular(CV)endpoints including progression of end-stage kidney disease in patients with DKD with T2DM at the top of reninangiotensin system blocker use.Another SGLT-2i,dapagliflozin,has also shown a significant reduction in the composite of renal and CV endpoints including death in patients with chronic kidney disease(CKD),regardless of T2DM status.Similar positive findings on renal outcomes were recently reported as a top-line result of the empagliflozin trial in patients with CKD regardless of T2DM.However,the full results of this trial have not yet been published.While the use of older steroidal mineralocorticoid receptor antagonists(MRAs)such as spironolactone in DKD is associated with a significant reduction in albuminuria outcomes,a novel non-steroidal MRA finerenone has additionally shown a significant reduction in the composite of hard renal and CV endpoints in patients with DKD and T2DM,with reasonably acceptable side effects.展开更多
INTRODUCTION: Since the outcomes associated with the use of renin-angiotensin-system inhibitors (RASi) by hemodialysis (HD) patients are not fully known, we investigated their effect on the cardiovascular mortality of...INTRODUCTION: Since the outcomes associated with the use of renin-angiotensin-system inhibitors (RASi) by hemodialysis (HD) patients are not fully known, we investigated their effect on the cardiovascular mortality of chronic HD patients. METHODS: Data from 388 HD patients (237 men and 151 women) who were routinely treated for at least 6 months were analyzed. Treatment with a RASi was the major predictor variable. The main outcome measure was cardiovascular mortality. Cox regression analysis was used to assess for the use of RASi and risk of death. RESULTS: Hypertension was diagnosed in 320 patients (82.5%), and 197 (50.8%) of them were treated with a RASi (treated group) and 191 (49.2%) were not (untreated group). The treated group had a higher prevalence of hypertension, history of congestive heart failure, and presence of ST-T changes. Kaplan-Meier analysis revealed a reduction in risk of cardiovascular death in the treated group during the follow-up period (fig. 2;log-rank: p=0.0379). The multivariate analysis showed that treatment with a RASi was also independently associated with reduced cardiovascular mortality (hazard ratio= 0.184;p=0.0161). CONCLUSIONS: The results of this study suggest a possible association between the treatment with RASi and reduced risk of cardiovascular mortality, independent of their effect of lowering blood pressure.展开更多
The renin-angiotensin system(RAS) regulates blood pressure(BP) homeostasis, systemic fluid volume and electrolyte balance. The RAS cascade includes over twenty peptidases, close to twenty angiotensin peptides and at l...The renin-angiotensin system(RAS) regulates blood pressure(BP) homeostasis, systemic fluid volume and electrolyte balance. The RAS cascade includes over twenty peptidases, close to twenty angiotensin peptides and at least six receptors. Out of these, angiotensin Ⅱ, angiotensin converting enzyme 1 and angiotensin Ⅱ type 1 receptor(AngⅡ-ACE1-AT1R) together with angiotensin(1-7), angiotensin converting enzyme 2 and Mas receptor(Ang(1-7)-ACE2-Mas R) are regarded as the main components of RAS. In addition to circulating RAS, local RA-system exists in various organs. Local RA-systems are regarded as tissue-specific regulatory system accounting for local effects and long term changes in different organs. Many of the central components such as the two main axes of RAS: AngⅡ-ACE1-AT1 R and Ang(1-7)-ACE2-Mas R, have been identified in the human eye. Furthermore, it has been shown that systemic antihypertensive RAS- inhibiting medications lower intraocular pressure(IOP). These findings suggest the crucial role of RAS not only in the regulation of BP but also in the regulation of IOP, and RAS potentially plays a role in the development of glaucoma and antiglaucomatous drugs.展开更多
Objective To explore the mechanisms of cyclosporin-induced chronic nephrotoxicity. Methods Radioimmunoassay was used to study the changes of plasma renin activity (PRA) ,plasma angiotensin Ⅱ(Ang Ⅱ),and Aldosterone a...Objective To explore the mechanisms of cyclosporin-induced chronic nephrotoxicity. Methods Radioimmunoassay was used to study the changes of plasma renin activity (PRA) ,plasma angiotensin Ⅱ(Ang Ⅱ),and Aldosterone after rats were given low salt diet and 30 mg?kg-1?d-1of CsAfor 28 days. The protective effects of Radix Salviae Miltiorrhizae or benazepril on these changes were also studied. Results In CsA-treated rats, PRA and Ang Ⅱ levels were significantly elevated as compared with control groups. The elevation was not influenced by injection of Radix Salviae Miltiorrhizae,but could be blocked markedly by benazepril. There was significant difference in Aldosterone levels among the groups except benazepril-treated group showing a decreased Aldosterone level. Conclusion Chronic cyclosporone nephropathy may be related to activation of renin-angiotensin system, especially to the elevation of Ang Ⅱ levels. The different effects of Radix Salviae Miltiorrhizae or benazepril on RAS suggest the different展开更多
Hepatic fibrosis is considered a common response to many chronic hepatic injuries.It is a multifunctional process that involves several cell types,cytokines,chemokines and growth factors leading to a disruption of hom...Hepatic fibrosis is considered a common response to many chronic hepatic injuries.It is a multifunctional process that involves several cell types,cytokines,chemokines and growth factors leading to a disruption of homeostatic mechanisms that maintain the liver ecosystem.In spite of many studies regarding the development of fibrosis,the understanding of the pathogenesis remains obscure.The hepatic tissue remodeling process is highly complex,resulting from the balance between collagen degradation and synthesis.Among the many mediators that take part in this process,the components of the Renin angiotensin system(RAS) have progressively assumed an important role.Angiotensin(Ang)□acts as a profibrotic mediator and Ang-(1-7),the newly recognized RAS component,appears to exert a counter-regulatory role in liver tissue.We briefly review the liver fibrosis process and current aspects of the RAS.This review also aims to discuss some experimental evidence regarding the participation of RAS mediators in the pathogenesis of liver fibrosis,focusing on the putative role of the ACE2-Ang-(1-7)-Mas receptor axis.展开更多
BACKGROUND Neoangiogenesis is one of the key pathogenetic mechanisms in hepatocellular carcinoma (HCC). Modulation of the renin-angiotensin system (RAS) by angiotensin-converting enzyme inhibitors (ACE-Is) and angiote...BACKGROUND Neoangiogenesis is one of the key pathogenetic mechanisms in hepatocellular carcinoma (HCC). Modulation of the renin-angiotensin system (RAS) by angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) seems to be a possible adjuvant therapy for HCC, due to the antiangiogenic and anti-fibrogenic activity of these drugs. AIM To elucidate the role of ARBs and ACE-Is in HCC. METHODS We performed an electronic search of the literature using the most accessed online databases (PubMed, Cochrane library, Scopus and Web of Science), entering the query terms "angiotensin-converting enzyme inhibitors" OR "ACE inhibitors" OR "ACE-I" AND "hepatocarcinoma*" OR "hepatocellular carcinoma;moreover "angiotensin II type 1 receptor blockers" OR "ARBs" AND "hepatocarcinoma*" OR "hepatocellular carcinoma". Eligibility criteria were:(1) prospective or retrospective clinical studies;(2) epidemiological studies;and (3) experimental studies conducted in vivo or in vitro. Abstracts, conference papers, and reviews were excluded a priori. We limited our literature search to articles published in English, in peer-reviewed journals.RESULTS Thirty-one studies were selected. Three interventional studies showed that ACEIs had a significant protective effect on HCC recurrence only when used in combination with vitamin K or branched chain aminoacids, without a significant increase in overall survival. Of six retrospective observational studies, mainly focused on overall survival, only one demonstrated a prolonged survival in the ACE-Is group, whereas the two that also evaluated tumor recurrence showed conflicting results. All experimental studies displayed beneficial effects of RAS inhibitors on hepatocarcinogenesis. Numerous experimental studies, conducted either on animals and cell cultures, demonstrated the anti-angiogenetic and antifibrotic effect of ACE-Is and ARBs, thanks to the suppression of some cytokines such as vascular endothelial growth factor, hypoxia-inducible factor-1a, transforming growth factor-beta and tumor necrosis factor alpha. All or parts of these mechanisms were demonstrated in rodents developing fewer HCC and preneoplastic lesions after receiving such drugs. CONCLUSION In humans, RAS inhibitors - alone or in combination - significantly suppressed the cumulative HCC recurrence, without prolonging patient survival, but some limitations intrinsic to these studies prompt further investigations.展开更多
The renin-angiotensin system(RAS)has been known for more than a century as a cascade that regulates body fluid balance and blood pressure.AngiotensinⅡ(AngⅡ)has many functions in different tissues;however it is on th...The renin-angiotensin system(RAS)has been known for more than a century as a cascade that regulates body fluid balance and blood pressure.AngiotensinⅡ(AngⅡ)has many functions in different tissues;however it is on the kidney that this peptide exerts its main functions.New enzymes,alternative routes for AngⅡformation or even active AngⅡ-derived peptides have now been described acting on AngⅡAT1or AT2receptors,or in receptors which have recently been cloned,such as Mas and AT4.Another interesting observation was that old members of the RAS,such as angiotensin converting enzyme(ACE),renin and prorenin,well known by its enzymatic activity,can also activate intracellular signaling pathways,acting as an outside-in signal transduction molecule or on the renin/(Pro)renin receptor.Moreover,the endocrine RAS,now is also known to have paracrine,autocrine and intracrine action ondifferent tissues,expressing necessary components for local AngⅡformation.This in situ formation,especially in the kidney,increases AngⅡlevels to regulate blood pressure and renal functions.These discoveries,such as the ACE2/Ang-(1-7)/Mas axis and its antangonistic effect rather than classical deleterious AngⅡeffects,improves the development of new drugs for treating hypertension and cardiovascular diseases.展开更多
Considerable evidence has accumulated to support the concept that the effects of the renin-agniotensin system can be mediated through two modes: endocrine and paracrine modes.
文摘The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.
文摘Background: Hypertension (HTN) is present in up to 90% of end stage kidney disease (ESRD) patients irrespective of the etiology of their kidney disease. Moreover, it is an important modifiable risk factor for progression to ESRD and its overall cardiovascular morbidity and mortality. Objective: to evaluate, prospectively, the role of Renin-Angiotensin-Aldosterone System blockade (RAAS) in HTN, resistant to 3 conventional antihypertensives, in patients on maintenance hemodialysis (MHD). Patients and methods: A total of 52 such patients were treated with Ramipril and 5 with Losartan after intolerable cough/shortness of breath following Ramipril-use. None of the patients had fluid depletion, renal artery stenosis and primary endocrinopathy. The study group was compared to a matched control group of MHD patients with normal blood pressure following 3 drugs-combination therapies. Results: All patients, with resistant HTN, had significant activation of RAAS system prior to treatment compared to inactive one in the control group. In those with resistant HTN, control of HTN, was established within 2 weeks of therapy and was associated with suppression of the RAAS. Such therapy was associated with minor side effects. Conclusion: Our study has shown that RAAS blockade is safe and effective in controlling such resistant HTN in MHD patients.
基金Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),Funda o de AmparoàPesquisa do Estado de S o Paulo(FAPESP)and Instituto Nacional de Neurociência Translacional(INNT),Programa de Núcleos de Excelência(PRONEX)(Brazil)
文摘The kallikrein-kinin system(KKS) is an intricate endogenous pathway involved in several physiological and pathological cascades in the brain. Due to the pathological effects of kinins in blood vessels and tissues, their formation and degradation are tightly controlled. Their components have been related to several central nervous system diseases such as stroke, Alzheimer's disease, Parkinson's disease, multiple sclerosis, epilepsy and others. Bradykinin and its receptors(B1R and B2R) may have a role in the pathophysiology of certain central nervous system diseases. It has been suggested that kinin B1R is up-regulated in pathological conditions and has a neurodegenerative pattern, while kinin B2R is constitutive and can act as a neuroprotective factor in many neurological conditions. The renin angiotensin system(RAS) is an important blood pressure regulator and controls both sodium and water intake. AngⅡ is a potent vasoconstrictor molecule and angiotensin converting enzyme is the major enzyme responsible for its release. AngⅡ acts mainly on the AT1 receptor, with involvement in several systemic and neurological disorders. Brain RAS has been associated with physiological pathways, but is also associated with brain disorders. This review describes topics relating to the involvement of both systems in several forms of brain dysfunction and indicates components of the KKS and RAS that have been used as targets in several pharmacological approaches.
文摘Available evidence points to a possible role of the renin-angiotensin system(RAS)in the pathophysiology of mood disorders and suicide.We carried out a critical analysis of literature data regarding this role,with a focus on the proposed association between RAS dysfunction and suicidal behavior.Epidemiological,genetic,and biochemical findings are described,and the pathophysiological hypothesis aiming at explaining the possible relationship between RAS and suicide are discussed.Available findings do support the involvement of the RAS in the neurobiology of suicide,although the exact mechanisms underlying this involvement are still unknown.
文摘Several pharmacological agents to prevent the progression of diabetic kidney disease(DKD)have been tested in patients with type 2 diabetes mellitus(T2DM)in the past two decades.With the exception of renin-angiotensin system blockers that have shown a significant reduction in the progression of DKD in 2001,no other pharmacological agent tested in the past two decades have shown any clinically meaningful result.Recently,the sodium-glucose cotransporter-2 inhibitor(SGLT-2i),canagliflozin,has shown a significant reduction in the composite of hard renal and cardiovascular(CV)endpoints including progression of end-stage kidney disease in patients with DKD with T2DM at the top of reninangiotensin system blocker use.Another SGLT-2i,dapagliflozin,has also shown a significant reduction in the composite of renal and CV endpoints including death in patients with chronic kidney disease(CKD),regardless of T2DM status.Similar positive findings on renal outcomes were recently reported as a top-line result of the empagliflozin trial in patients with CKD regardless of T2DM.However,the full results of this trial have not yet been published.While the use of older steroidal mineralocorticoid receptor antagonists(MRAs)such as spironolactone in DKD is associated with a significant reduction in albuminuria outcomes,a novel non-steroidal MRA finerenone has additionally shown a significant reduction in the composite of hard renal and CV endpoints in patients with DKD and T2DM,with reasonably acceptable side effects.
文摘INTRODUCTION: Since the outcomes associated with the use of renin-angiotensin-system inhibitors (RASi) by hemodialysis (HD) patients are not fully known, we investigated their effect on the cardiovascular mortality of chronic HD patients. METHODS: Data from 388 HD patients (237 men and 151 women) who were routinely treated for at least 6 months were analyzed. Treatment with a RASi was the major predictor variable. The main outcome measure was cardiovascular mortality. Cox regression analysis was used to assess for the use of RASi and risk of death. RESULTS: Hypertension was diagnosed in 320 patients (82.5%), and 197 (50.8%) of them were treated with a RASi (treated group) and 191 (49.2%) were not (untreated group). The treated group had a higher prevalence of hypertension, history of congestive heart failure, and presence of ST-T changes. Kaplan-Meier analysis revealed a reduction in risk of cardiovascular death in the treated group during the follow-up period (fig. 2;log-rank: p=0.0379). The multivariate analysis showed that treatment with a RASi was also independently associated with reduced cardiovascular mortality (hazard ratio= 0.184;p=0.0161). CONCLUSIONS: The results of this study suggest a possible association between the treatment with RASi and reduced risk of cardiovascular mortality, independent of their effect of lowering blood pressure.
基金Supported by Päivikki and Sakari Sohlberg Foundationthe Eye Foundation+2 种基金the Glaucoma Research Foundation Luxthe Competitive Research Funding of Tampere University Hospital,No.9S072and the Foundation for Clinical Chemistry Research.
文摘The renin-angiotensin system(RAS) regulates blood pressure(BP) homeostasis, systemic fluid volume and electrolyte balance. The RAS cascade includes over twenty peptidases, close to twenty angiotensin peptides and at least six receptors. Out of these, angiotensin Ⅱ, angiotensin converting enzyme 1 and angiotensin Ⅱ type 1 receptor(AngⅡ-ACE1-AT1R) together with angiotensin(1-7), angiotensin converting enzyme 2 and Mas receptor(Ang(1-7)-ACE2-Mas R) are regarded as the main components of RAS. In addition to circulating RAS, local RA-system exists in various organs. Local RA-systems are regarded as tissue-specific regulatory system accounting for local effects and long term changes in different organs. Many of the central components such as the two main axes of RAS: AngⅡ-ACE1-AT1 R and Ang(1-7)-ACE2-Mas R, have been identified in the human eye. Furthermore, it has been shown that systemic antihypertensive RAS- inhibiting medications lower intraocular pressure(IOP). These findings suggest the crucial role of RAS not only in the regulation of BP but also in the regulation of IOP, and RAS potentially plays a role in the development of glaucoma and antiglaucomatous drugs.
文摘Objective To explore the mechanisms of cyclosporin-induced chronic nephrotoxicity. Methods Radioimmunoassay was used to study the changes of plasma renin activity (PRA) ,plasma angiotensin Ⅱ(Ang Ⅱ),and Aldosterone after rats were given low salt diet and 30 mg?kg-1?d-1of CsAfor 28 days. The protective effects of Radix Salviae Miltiorrhizae or benazepril on these changes were also studied. Results In CsA-treated rats, PRA and Ang Ⅱ levels were significantly elevated as compared with control groups. The elevation was not influenced by injection of Radix Salviae Miltiorrhizae,but could be blocked markedly by benazepril. There was significant difference in Aldosterone levels among the groups except benazepril-treated group showing a decreased Aldosterone level. Conclusion Chronic cyclosporone nephropathy may be related to activation of renin-angiotensin system, especially to the elevation of Ang Ⅱ levels. The different effects of Radix Salviae Miltiorrhizae or benazepril on RAS suggest the different
文摘Hepatic fibrosis is considered a common response to many chronic hepatic injuries.It is a multifunctional process that involves several cell types,cytokines,chemokines and growth factors leading to a disruption of homeostatic mechanisms that maintain the liver ecosystem.In spite of many studies regarding the development of fibrosis,the understanding of the pathogenesis remains obscure.The hepatic tissue remodeling process is highly complex,resulting from the balance between collagen degradation and synthesis.Among the many mediators that take part in this process,the components of the Renin angiotensin system(RAS) have progressively assumed an important role.Angiotensin(Ang)□acts as a profibrotic mediator and Ang-(1-7),the newly recognized RAS component,appears to exert a counter-regulatory role in liver tissue.We briefly review the liver fibrosis process and current aspects of the RAS.This review also aims to discuss some experimental evidence regarding the participation of RAS mediators in the pathogenesis of liver fibrosis,focusing on the putative role of the ACE2-Ang-(1-7)-Mas receptor axis.
文摘BACKGROUND Neoangiogenesis is one of the key pathogenetic mechanisms in hepatocellular carcinoma (HCC). Modulation of the renin-angiotensin system (RAS) by angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) seems to be a possible adjuvant therapy for HCC, due to the antiangiogenic and anti-fibrogenic activity of these drugs. AIM To elucidate the role of ARBs and ACE-Is in HCC. METHODS We performed an electronic search of the literature using the most accessed online databases (PubMed, Cochrane library, Scopus and Web of Science), entering the query terms "angiotensin-converting enzyme inhibitors" OR "ACE inhibitors" OR "ACE-I" AND "hepatocarcinoma*" OR "hepatocellular carcinoma;moreover "angiotensin II type 1 receptor blockers" OR "ARBs" AND "hepatocarcinoma*" OR "hepatocellular carcinoma". Eligibility criteria were:(1) prospective or retrospective clinical studies;(2) epidemiological studies;and (3) experimental studies conducted in vivo or in vitro. Abstracts, conference papers, and reviews were excluded a priori. We limited our literature search to articles published in English, in peer-reviewed journals.RESULTS Thirty-one studies were selected. Three interventional studies showed that ACEIs had a significant protective effect on HCC recurrence only when used in combination with vitamin K or branched chain aminoacids, without a significant increase in overall survival. Of six retrospective observational studies, mainly focused on overall survival, only one demonstrated a prolonged survival in the ACE-Is group, whereas the two that also evaluated tumor recurrence showed conflicting results. All experimental studies displayed beneficial effects of RAS inhibitors on hepatocarcinogenesis. Numerous experimental studies, conducted either on animals and cell cultures, demonstrated the anti-angiogenetic and antifibrotic effect of ACE-Is and ARBs, thanks to the suppression of some cytokines such as vascular endothelial growth factor, hypoxia-inducible factor-1a, transforming growth factor-beta and tumor necrosis factor alpha. All or parts of these mechanisms were demonstrated in rodents developing fewer HCC and preneoplastic lesions after receiving such drugs. CONCLUSION In humans, RAS inhibitors - alone or in combination - significantly suppressed the cumulative HCC recurrence, without prolonging patient survival, but some limitations intrinsic to these studies prompt further investigations.
基金Supported by Carlos Chagas Filho Rio de Janeiro State Research Foundation(FAPERJ)National Institute of Science and Technology for Structural Biology and BioimagingBrazilian National Research Council(CNPq)
文摘The renin-angiotensin system(RAS)has been known for more than a century as a cascade that regulates body fluid balance and blood pressure.AngiotensinⅡ(AngⅡ)has many functions in different tissues;however it is on the kidney that this peptide exerts its main functions.New enzymes,alternative routes for AngⅡformation or even active AngⅡ-derived peptides have now been described acting on AngⅡAT1or AT2receptors,or in receptors which have recently been cloned,such as Mas and AT4.Another interesting observation was that old members of the RAS,such as angiotensin converting enzyme(ACE),renin and prorenin,well known by its enzymatic activity,can also activate intracellular signaling pathways,acting as an outside-in signal transduction molecule or on the renin/(Pro)renin receptor.Moreover,the endocrine RAS,now is also known to have paracrine,autocrine and intracrine action ondifferent tissues,expressing necessary components for local AngⅡformation.This in situ formation,especially in the kidney,increases AngⅡlevels to regulate blood pressure and renal functions.These discoveries,such as the ACE2/Ang-(1-7)/Mas axis and its antangonistic effect rather than classical deleterious AngⅡeffects,improves the development of new drugs for treating hypertension and cardiovascular diseases.
文摘Considerable evidence has accumulated to support the concept that the effects of the renin-agniotensin system can be mediated through two modes: endocrine and paracrine modes.
