Adrenomedullin (AM) is a potent vasodilator peptide whose major source is the vascular wall. In the present study, the mechanism of release of AM was investigated in the rat mesenteric resistance artery. The isolated mesenteric vascular bed was perfused with Krebs solution at a constant flow rate (5 ml/min) and AM in the perfusate was measured by a highly sensitive enzyme immunoassay (Immunoenzymometric assay; IEMA) method. In preparations without endothelium, spontaneous release of AM was detected in the perfusate (68.7+/-5.8 fmol/ml, n=45). Periarterial nerve stimulation (PNS, 4 and 8 Hz) caused 11.4+/-3.9% (4 Hz) and 9.1+/-3.5% (8 Hz) decreases in the spontaneous release of AM. Removal of Ca2+ from the medium did not affect the spontaneous AM release, but abolished the PNS-induced inhibition of spontaneous AM release. Perfusion of 10nM calcitonin gene-related peptide (CGRP) or 0.1 microM capsaicin (inducer of CGRP release) inhibited significantly the spontaneous AM release. PNS (8 Hz)-induced inhibition of spontaneous AM release was antagonized by CGRP(8-37) (CGRP receptor antagonist). These results suggest that AM is mainly released from vascular smooth muscle cells of the rat mesenteric artery and endogenous or exogenous CGRP inhibits AM release.
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http://dx.doi.org/10.1016/j.peptides.2005.04.014 | DOI Listing |
Cell Commun Signal
January 2025
Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, 430022, China.
Efferocytosis is a mechanism by which phagocytes efficiently clear apoptotic cells, averting their secondary necrosis and the subsequent release of potentially immunogenic or cytotoxic substances that can trigger strong immune and inflammatory responses. During efferocytosis, the metabolic pathways of phagocytes are transformed, which, along with the catabolism of apoptotic cargo, can affect their function and inflammatory state. Extensive apoptosis occurs during placental development, and some studies reported the immunomodulatory effects of efferocytosis at the maternal-fetal interface.
View Article and Find Full Text PDFResuscitation
January 2025
Department of Medicine, University of Washington, Seattle, WA; King County Emergency Medical Services, Seattle-King County Department of Public Health, Seattle, WA.
Background: Prior studies have proposed defibrillator biosignal algorithms which characterize cardiac arrest rhythm and physiologic status. We evaluated whether a novel, individualized resuscitation strategy that integrates multiple ECG and impedance-based algorithms could reduce CPR interruptions and better align rescuer actions with patient-specific physiology.
Methods: In a retrospective cohort of ventricular fibrillation out-of-hospital cardiac arrests, observed rescuer actions (rhythm analysis, shock delivery, pulse checks, and drug therapy) were compared to hypothetical actions recommended by the proposed individualized strategy.
Biophys J
January 2025
Department of Chemical Engineering, Columbia University, New York, NY 10027. Electronic address:
Membrane fusion is central to fundamental cellular processes such as exocytosis, when an intracellular machinery fuses membrane-enclosed vesicles to the plasma membrane for contents release. The core machinery components are the SNARE proteins. SNARE complexation pulls the membranes together, but the fusion mechanism remains unclear.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Chemistry and Environment, Southwest Minzu University, Chengdu 610041 China. Electronic address:
We developed antibiotic-based micelles with bone-targeting and charge-switchable properties (P-CASMs) for treating infectious osteomyelitis. The amphiphilic molecules are formed by combining ciprofloxacin (CIP) with ligand 1 through a mild salifying reaction, and spontaneously self-assemble into antibiotic-based micelles (ASMs) in aqueous solution. Acrylate groups on ligand 1 enable cross-linking of ASMs with pentaerythritol tetra(mercaptopropionate) via a click reaction, forming pH-sensitive cross-linked micelles (CASMs).
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Graduate School of Life and Environmental Sciences, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 400-8510 Kofu, Japan.
Background: Sperm represent a heterogeneous population crucial for male reproductive success. Additionally, sperm undergo dynamic changes during maturation and capacitation. Despite these well-established processes, the complex nature of sperm heterogeneity and membrane dynamics remains elusive.
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