Search results for " angiotensin"
showing 10 items of 72 documents
Oxidative stress in vascular disease: causes, defense mechanisms and potential therapies
2007
Endothelial cells control vascular homeostasis by generating paracrine factors that regulate vascular tone, inhibit platelet function, prevent adhesion of leukocytes, and limit proliferation of vascular smooth muscle. The dominant factor responsible for many of those effects is endothelium-derived nitric oxide (NO). Endothelial dysfunction characterized by enhanced inactivation or reduced synthesis of NO, alone or in combination, is seen in conjunction with risk factors for cardiovascular disease. Endothelial dysfunction can promote vasospasm, thrombosis, vascular inflammation, and proliferation of the intima. Vascular oxidative stress and increased production of reactive oxygen species con…
Angiotensin II Type 1 Receptor Antibodies Are Higher in Lupus Nephritis and Vasculitis than Other Glomerulonephritis Patients
2022
AbstractAngiotensin II type 1 receptor (AT1R) antibodies are considered non-HLA (human leukocyte antigen) antibodies connected with humoral rejection after kidney transplantation. The role of AT1R antibodies in the pathogenesis of glomerular diseases and systemic vasculitis is unknown. We assessed the level of AT1R antibodies in 136 patients with different types of glomerulonephritis and systemic vasculitis and we observed kidney function and proteinuria, serum albumin and total protein levels for 2 years. The mean levels of AT1R antibodies were the following: 6.00 ± 1.31 U/ml in patients with membranous nephropathy (n = 18), 5.67 ± 1.31 U/ml with focal and segmental glomerulosclerosis (n =…
DNA damage response at telomeres boosts the transcription of SARS-CoV-2 receptor ACE2 during aging
2021
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease 2019 (COVID-19), known to be more common in the elderly, who also show more severe symptoms and are at higher risk of hospitalization and death. Here, we show that the expression of the angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 cell receptor, increases during aging in mouse and human lungs. ACE2 expression increases upon telomere shortening or dysfunction in both cultured mammalian cells and in vivo in mice. This increase is controlled at the transcriptional level, and Ace2 promoter activity is DNA damage response (DDR)-dependent. Both pharmacological global DDR inhibition of ATM kin…
Angiotensin II type-2 receptors and colonic dysmotility associated to experimental colitis in rats
2016
Angiotensin II (Ang II) is a newly discovered modulator of intestinal motility, mainly via activation of excitatory AT1 receptors (AT1R). We demonstrated that during gut inflammation there is a recruitment of inhibitory AT2 receptors (AT2R) which would counteract the AT1R-induced effects. Our objective was to explore the consequence of AT2R activation in the pathogenesis of experimental colitis. Colitis was induced in rats by intrarectal administration of 2,4-Dinitrobenzene sulfonic acid (DNBS). Colonic damage was assessed by macro- and microscopic scores, myeloperoxidase activity and inflammatory cytokine expression on day 6 after colitis induction. Colonic contractility was recorded in vi…
Regulación por estradiol de la producción de Angiotensina 1-7 y papel del receptor Mas en la producción de óxido nítrico en células endoteliales huma…
2017
El sistema renina-angiotensina intracelular (SRA) está formado por un conjunto de enzimas y metabolitos que se han relacionado con la regulación de la función cardiovascular y con la fisiopatología de la hipertensión arterial. El SRA clásico o circulante interviene en la regulación vascular principalmente con los péptidos bioactivos angiotensina (Ang) I y Ang II. La enzima que regula el paso de Ang I a Ang II es la enzima de conversión de la angiotensina 1 (ECA-1, la primera que se describió). En el año 2000 se descubrió que la enzima de conversión de la angiotensina 2 (ECA-2) convertía la Ang II en Ang 1-7. La Ang 1-7 es una molécula del SRA que tiene efecto fundamentalmente vasodilatador.…
ROLE OF RENIN-ANGIOTENSIN SYSTEM IN COLONIC DYSMOTILITY ASSOCIATED WITH BOWEL INFLAMMATION IN RATS
2015
Dysregulation of different mediator systems could contribute to the gut dismotility in inflammatory bowel diseases (IBDs), chronic disorders characterized by an exasperated immune response disturbing gut functions. Among these, Angiotensin II (Ang II), the main peptide of renin-angiotensin system (RAS), can participate in inflammatory responses and RAS components are increased in IBD patients. Since RAS has emerged as gut motility regulator, our objectives was to investigate, in an IBD rat model, the RAS functionality and its eventual contribution to colonic dismotility. Experimental colitis was induced in rats by intracolonic administration of 2,4-dinitrobenzenesulfonic acid (DNBS). Drug e…
Spectrum of mutations in the renin-angiotensin system genes in autosomal recessive renal tubular dysgenesis
2012
Autosomal recessive renal tubular dysgenesis (RTD) is a severe disorder of renal tubular development characterized by early onset and persistent fetal anuria leading to oligohydramnios and the Potter sequence, associated with skull ossification defects. Early death occurs in most cases from anuria, pulmonary hypoplasia, and refractory arterial hypotension. The disease is linked to mutations in the genes encoding several components of the renin-angiotensin system (RAS): AGT (angiotensinogen), REN (renin), ACE (angiotensin-converting enzyme), and AGTR1 (angiotensin II receptor type 1). Here, we review the series of 54 distinct mutations identified in 48 unrelated families. Most of them are no…
Long-term effectiveness of agalsidase alfa enzyme replacement in Fabry disease: A Fabry Outcome Survey analysis
2015
Outcomes from 5 years of treatment with agalsidase alfa enzyme replacement therapy (ERT) for Fabry disease in patients enrolled in the Fabry Outcome Survey (FOS) were compared with published findings for untreated patients with Fabry disease. Data were extracted from FOS, a Shire-sponsored database, for comparison with data from three published studies. Outcomes evaluated were the annualized rate of change in estimated glomerular filtration rate (eGFR) and left ventricular mass indexed to height (LVMI) as well as time to and ages at a composite morbidity endpoint and at death. FOS data were extracted for 740 treated patients who were followed for a median of ~ 5 years. Compared with no trea…
Angiotensin II induces leukocyte-endothelial cell interactions in vivo via AT(1) and AT(2) receptor-mediated P-selectin upregulation.
2000
Background —Angiotensin II (Ang II) plays a critical role in the development of vascular lesions in hypertension, atherosclerosis, and several renal diseases. Because Ang II may contribute to the leukocyte recruitment associated with these pathological states, the aim of the present study was to assess the role of Ang II in leukocyte–endothelial cell interactions in vivo. Methods and Results —Intravital microscopy of the rat mesenteric postcapillary venules was used. Sixty minutes of superfusion with 1 nmol/L Ang II induced a significant increase in leukocyte rolling flux (83.8±20.7 versus 16.4±3.1 cells/min), adhesion (11.4±1.0 versus 0.8±0.5 cells/100 μm), and emigration (4.0±0.7 versus …
In vivo antihypertensive mechanism of lactoferrin-derived peptides: Reversion of angiotensin I- and angiotensin II-induced hypertension in Wistar rats
2015
Novel peptides with antihypertensive effects in SHR rats have previously been identified in lactoferrin (LF) hydrolysates. To investigate their in vivo antihypertensive mechanism, we have assessed the blood pressure lowering effects of two of these LF-derived peptides (RPYL and DPYKLRP) in Wistar rats subjected to either angiotensin I- or angiotensin II-induced hypertension. Blood pressure was measured by the tail-cuff method, hypertension was induced by subcutaneous infusion of angiotensins, and then captopril, valsartan or LF-derived peptides orally administered. Angiotensin I- and angiotensin II-induced hypertension were reversed by captopril and valsartan, respectively. RPYL and DPYKLRP…