ArticleExperimental physiology2008
Angiotensin-converting enzyme 2 catalytic activity in human plasma is masked by an endogenous inhibitor.
Article in Experimental physiology, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 69 papers, 1 of them a synthesis that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
69 citing papers in PubMed, 1 synthesis or guideline pooled it.
- COVID-19 in comorbid chronic diseased patients, pregnant and lactating women: pathophysiology, available drug treatment, and the most suitable protocol regimen in each group.Inflammopharmacology · 2025Pooled it
- A pilot study to assess the circulating renin-angiotensin system in COVID-19 acute respiratory failure.American journal of physiology. Lung cellular and molecular physiology · 2021Trial
- Increased Cerebrospinal Fluid Angiotensin-Converting Enzyme 2 Fragments as a Read-Out of Brain Infection in Patients With COVID-19 Encephalopathy.The Journal of infectious diseases · 2025Article
- Novel Antihypertensive Medications to Target the Renin-Angiotensin System: Mechanisms and Research.Reviews in cardiovascular medicine · 2025Review
- Clinical studies in Myxomatous Mitral Valve Disease dogs: most prescribed ACEI inhibits ACE2 enzyme activity and ARB increases AngII pool in plasma.Hypertension research : official journal of the Japanese Society of Hypertension · 2025Article
- Genetically edited human placental organoids cast new light on the role of ACE2.Cell death & disease · 2025Article
- Article
- The Renin-Angiotensin System (RAS) in COVID-19 Disease: Where We Are 3 Years after the Beginning of the Pandemic.Microorganisms · 2024Review
- Dietary fish intake increased the concentration of soluble ACE2 in rats: can fish consumption reduce the risk of COVID-19 infection through interception of SARS-CoV-2 by soluble ACE2?The British journal of nutrition · 2023Article
- Renin-Angiotensin System and Sex Differences in COVID-19: A Critical Assessment.Circulation research · 2023Review
- Association between soluble angiotensin-converting enzyme 2 in saliva and SARS-CoV-2 infection: a cross-sectional study.Scientific reports · 2023Article
- Maternal plasma angiotensin 1-7 concentration is related to twin pregnancy chorionicity in the third trimester of pregnancy.Frontiers in endocrinology · 2023Observational
- Single Nucleotide Variants (SNVs) of Angiotensin-Converting Enzymes (ACE1 and ACE2): A Plausible Explanation for the Global Variation in COVID-19 Prevalence.Journal of the renin-angiotensin-aldosterone system : JRAAS · 2023Review
- Early shedding of membrane-bounded ACE2 could be an indicator for disease severity in SARS-CoV-2.Biochimie · 2022Article
- Metalloprotease-Dependent S2'-Activation Promotes Cell-Cell Fusion and Syncytiation of SARS-CoV-2.Viruses · 2022Article
- Plasma Angiotensin Converting Enzyme 2 (ACE2) Activity in Healthy Controls and Patients with Cardiovascular Risk Factors and/or Disease.Journal of personalized medicine · 2022Article
- Decrease in Angiotensin-Converting Enzyme activity but not concentration in plasma/lungs in COVID-19 patients offers clues for diagnosis/treatment.Molecular therapy. Methods & clinical development · 2022Article
- The Need for Individualized Risk Assessment in Cardiovascular Disease.Journal of personalized medicine · 2022Review
- Functional ACE2 deficiency leading to angiotensin imbalance in the pathophysiology of COVID-19.Reviews in endocrine & metabolic disorders · 2022Review
- Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection.Nature immunology · 2022Article
9 more citing papers are in PubMed but not listed here.
Corrections and comments
- Erratum issuedCorrigendum.2015 · Manohar, Jay [corrected to Ramchand, Jay]
Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Angiotensin-converting enzyme 2 (ACE2) is thought to act in an opposing manner to its homologue, angiotensin-converting enzyme (ACE), by inactivating the vasoconstrictor peptide angiotensin II and generating the vasodilatory fragment, angiotensin(1-7). Both ACE and ACE2 are membrane-bound ectoenzymes and may circulate in plasma as a consequence of a proteolytic shedding event. In this study, we show that ACE2 circulates in human plasma, but its activity is suppressed by the presence of an endogenous inhibitor. Partial purification of this inhibitor indicated that the inhibitor is small, hydrophilic and cationic, but not a divalent metal cation. These observations led us to develop a method for removal of the inhibitor, thus allowing detection of plasma ACE2 levels using a sensitive quenched fluorescent substrate-based assay. Using this technique, ACE2 activity measured in plasma from healthy volunteers (n = 18) ranged from 1.31 to 8.69 pmol substrate cleaved min-1 ml-1 (mean +/- s.e.m., 4.44 +/- 0.56 pmol min-1 ml-1). Future studies of patients with cardiovascular, renal and liver disease will determine whether plasma ACE2 is elevated in parallel with increased tissue levels observed in these conditions.
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