Background: Erythrocyte-derived depressing factor (EDDF), a novel hypotensive factor purified from human erythrocytes, elicits endothelium-dependent vasorelaxation by reducing intracellular Ca2+ in vascular smooth muscle cells. However, its cardiac response is unknown.
Objective: This study was designed to examine the cardiac contractile response of EDDF under both normotensive and hypertensive conditions.
Methods: Ventricular myocytes were isolated from adult male spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) normotensive rats. Mechanical properties were evaluated using an IonOptix MyoCam system and intracellular Ca2+ was measured with fura-2 fluorescence. Myocytes were electrically stimulated to contract at 0.5 Hz. The contractile properties analyzed included peak shortening (PS), time-to-PS (TPS), time-to-90% re-lengthening (TR(90)), maximal velocity of shortening/re-lengthening (+/- dl/dt), fura-fluorescence intensity change (DeltaFFI), and fura-fluorescence decay rate (tau).
Results: SHR rats displayed significantly elevated blood pressure. EDDF (10-9-10-4 g/ml) did not affect PS, TPS, TR(90), DeltaFFI and tau but depressed +/- dl/dt at higher doses in WKY myocytes. However, EDDF depressed PS, +/- dl/dt and DeltaFFI, shortened TPS without affecting TR(90) and tau in SHR myocytes. Pretreatment of the myocytes with the nitric oxide synthase inhibitor Nvarpi-nitro-l-arginine methyl ester (l-NAME) did not affect the EDDF-induced inhibition of PS and +/- dl/dt in SHR myocytes but unmasked an EDDF-induced negative response in WKY myocytes.
Conclusions: These data indicate that EDDF may participate in the modulation of cardiac contractile function under hypertensive, but not normotensive, conditions. The cardiac depressive effect of EDDF is unlikely due to release of nitric oxide, as suggested in vascular smooth muscles.
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http://dx.doi.org/10.1097/00004872-200306000-00019 | DOI Listing |
Microbiol Spectr
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Key Laboratory of Medicinal Plant and Animal Resources of the Qinghai-Tibetan Plateau in Qinghai Province, Academy of Plateau Science and Sustainability, School of Life Science, Qinghai Normal University, Xining, China.
Unlabelled: The biodiversity of CO-assimilating bacterial communities is pivotal for carbon sequestration in agricultural systems. Changes in the diversity, structure, and activity of the soil chemolithoautotrophic bacteria were examined in four agricultural areas, Dulan (DL), Gonghe (GH), Huzhu (HZ), and Datong (DT) counties in Qinghai Province, where wheat, oilseed rape, and barley were planted. This process was performed using Illumina amplicon sequencing of the ribulose-1,5-bisphosphatecarboxylase/oxygenase (RubisCO) gene ( Form I) and activity data.
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Université Paris-Saclay, Inserm UMR1030, Laboratory of Molecular Radiotherapy and Therapeutic Innovation, Villejuif, France.
Purinergic receptors and NOD-like receptor protein 3 (NLRP3) inflammasome regulate inflammation and viral infection, but their effects on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain poorly understood. Here, we report that the purinergic receptor P2X7 and NLRP3 inflammasome are cellular host factors required for SARS-CoV-2 infection. Lung autopsies from patients with severe coronavirus disease 2019 (COVID-19) reveal that NLRP3 expression is increased in host cellular targets of SARS-CoV-2 including alveolar macrophages, type II pneumocytes and syncytia arising from the fusion of infected macrophages, thus suggesting a potential role of NLRP3 and associated signaling pathways to both inflammation and viral replication.
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December 2023
Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China.
Heart failure with preserved ejection fraction (HFpEF) displays normal or near-normal left ventricular ejection fraction, diastolic dysfunction, cardiac hypertrophy, and poor exercise capacity. Berberine, an isoquinoline alkaloid, possesses cardiovascular benefits. Adult male mice were assigned to chow or high-fat diet with L-NAME ("two-hit" model) for 15 weeks.
View Article and Find Full Text PDFHeliyon
July 2023
Department of Internal Medicine, Cardiovascular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
Aims: Upregulation of Ca/calmodulin-dependent protein kinase II (CaMKII) contributes to the pathogenesis of cardiovascular disease, including hypertension. Transgenic rats expressing the human angiotensinogen gene [TGR (hAGT)L1623] are a new novel humanized model of hypertension that associates with declines in cardiac contractile function and β-adrenergic receptor (AR) reserve. The molecular mechanisms are unclear.
View Article and Find Full Text PDFJ Biomed Sci
March 2023
Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program National Institute On Aging, NIH, Baltimore, MD, 21224, USA.
Background: Quelling microglial-induced excessive neuroinflammation is a potential treatment strategy across neurological disorders, including traumatic brain injury (TBI), and can be achieved by thalidomide-like drugs albeit this approved drug class is compromised by potential teratogenicity. Tetrafluorobornylphthalimide (TFBP) and tetrafluoronorbornylphthalimide (TFNBP) were generated to retain the core phthalimide structure of thalidomide immunomodulatory imide drug (IMiD) class. However, the classical glutarimide ring was replaced by a bridged ring structure.
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