A secondary metabolite from sponges of the genus Agelas, 4,5-dibromopyrrole-2-carboxylic acid, which is well known as feeding deterrent, was investigated for effects on the cellular calcium homeostasis in PC12 cells. 4,5-Dibromopyrrole-2-carboxylic acid did not change intracellular calcium levels if applied alone without cell depolarization. During depolarization of the cellular membrane using high potassium solution, a dose dependent reduction of intracellular calcium elevation was revealed utilizing Fura II as calcium indicator. Significant reduction was seen at concentrations higher than 30μM in a series of experiments, but in single experiments a concentration of 300nM was still reversible effective. In the same concentration range, the onset of depolarization induced calcium elevations was significantly delayed by 4,5-dibromopyrrole-2-carboxylic acid. Dose dependent reduction and delay of depolarization evoked calcium elevations are probably due to a reduction of calcium entry via voltage operated calcium channels. One cellular mode of action of the feeding deterrent potential of 4,5-dibromopyrrole-2-carboxylic acid to fishes may be an interaction with the cellular calcium homeostasis of exposed cells.
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http://dx.doi.org/10.1016/j.etap.2004.12.003 | DOI Listing |
Annu Rev Immunol
January 2025
3Department of Environmental Medicine and Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA; email:
Initially discovered for its role mediating the deleterious effects of environmental contaminants, the aryl hydrocarbon receptor (AHR) is now known to be a crucial regulator of the immune system. The expanding list of AHR ligands includes synthetic and naturally derived molecules spanning pollutants, phytochemicals, pharmaceuticals, and substances derived from amino acids and microorganisms. The consequences of engaging AHR vary, depending on factors such as the AHR ligand, cell type, immune challenge, developmental state, dose, and timing of exposure relative to the immune stimulus.
View Article and Find Full Text PDFN Engl J Med
January 2025
From the Department of Medicine, University of Auckland, Auckland, New Zealand (M.J.B., Z.N., A.M., C.G., V.P., B.M., A.G., I.R.R., G.G., A.H.); the Department of Psychology, Stanford University, Stanford, CA (C.G.); and the Department of Radiology, Starship Hospital, Auckland, New Zealand (S.B.).
Background: Zoledronate prevents fractures in older women when administered every 12 to 18 months, but its effects on bone density and bone turnover persist beyond 5 years. Whether infrequent zoledronate administration would prevent vertebral fractures in early postmenopausal women is unknown.
Methods: We conducted a 10-year, prospective, double-blind, randomized, placebo-controlled trial involving early postmenopausal women (50 to 60 years of age) with bone mineral density T scores lower than 0 and higher than -2.
ACS Nano
January 2025
National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064, P. R. China.
Inadequate vascularization significantly hampers wound recovery by limiting nutrient delivery. To address this challenge, we extracted membrane vesicles from (LMVs) and identified their angiogenic potential via transcriptomic analysis. We further developed a composite hydrogel system (Gel-LMVs) by anchoring LMVs within carboxylated chitosan and cross-linking it with oxidized hyaluronic acid through a Schiff base reaction.
View Article and Find Full Text PDFBlood Adv
January 2025
Sanquin, Amsterdam, Netherlands.
In Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP), patients develop antibodies against ADAMTS13. The majority of patients exhibit inhibitory anti-spacer antibodies. Non-inhibitory antibodies binding to the carboxy-terminal CUB domains have been suggested to enhance the clearance of ADAMTS13 in iTTP.
View Article and Find Full Text PDFHepatol Commun
February 2025
Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
Background: Although bariatric and metabolic surgical methods, including duodenal-jejunal bypass (DJB), were shown to improve metabolic dysfunction-associated steatotic liver disease (MASLD) in clinical trials and experimental rodent models, their underlying mechanisms remain unclear. The present study therefore evaluated the therapeutic effects and mechanisms of action of DJB in rats with MASLD.
Methods: Rats with MASLD were randomly assigned to undergo DJB or sham surgery.
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