The existence and properties of volume-activated Cl- currents were studied in 15 different cell types (endothelium: human umbilical vein, human aorta, bovine pulmonary artery; fibroblasts: Swiss 3T3, L, C3H 10T1/2 and COS-1; epithelium: KB3, HeLa and A6; blood cells: RBL-2H3 and Jurkat; endothelioma cells derived from both subcutaneous and thymic hemangiomas; skin: IGR1 melanoma). Volume-activated Cl- currents with common characteristics, i.e. small conductance, outward rectification, higher permeability for iodide than for chloride and sensitivity to block by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) could be elicited in all cells. The block of this current by tamoxifen and dideoxyforskolin is different for the various cell types, as well as the time course and the amplitude of the responses induced by repetitive applications of hypotonicity. Volume-activated Cl- channels with similar biophysical properties are therefore wide-spread among mammalian cells. This may reflect either a single Cl- channel that is ubiquitously expressed or a family of functionally related Cl- channels with cell specific expression patterns.
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http://dx.doi.org/10.1007/BF00724520 | DOI Listing |
Am J Physiol Cell Physiol
August 2024
Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, Utah, United States.
Aqueous humor drainage from the anterior eye determines intraocular pressure (IOP) under homeostatic and pathological conditions. Swelling of the trabecular meshwork (TM) alters its flow resistance but the mechanisms that sense and transduce osmotic gradients remain poorly understood. We investigated TM osmotransduction and its role in calcium and chloride homeostasis using molecular analyses, optical imaging, and electrophysiology.
View Article and Find Full Text PDFHepatology
November 2022
Department of Pediatrics, University of Pittsburgh Medical Center Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Background And Aims: Chloride (Cl ) channels in the apical membrane of biliary epithelial cells (BECs), also known as cholangiocytes, provide the driving force for biliary secretion. Although two Cl channels have been identified on a molecular basis, the Cystic Fibrosis Transmembrane Conductance Regulator and Transmembrane Member 16A, a third Cl channel with unique biophysical properties has been described. Leucine-Rich Repeat-Containing Protein 8, subfamily A (LRRC8A) is a newly identified protein capable of transporting Cl in other epithelium in response to cell swelling.
View Article and Find Full Text PDFBiochem Pharmacol
November 2021
Guangdong Provincial Key Laboratory of Pharmaceutical Bioactive Substances and School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, PR China. Electronic address:
The representative morphological features of pyroptosis are excessive cell swelling and subsequent membrane rupture. However, the mechanism underlying the cell's inherent inability to regulate volume during the progression of pyroptosis is poorly understood. In the current study, we found that both volume-activated chloride currents (I) and the regulatory volume decrease (RVD) were markedly decreased in bone marrow-derived macrophages (BMDMs) undergoing pyroptosis induced by lipopolysaccharides (LPS) and nigericin.
View Article and Find Full Text PDFNaunyn Schmiedebergs Arch Pharmacol
March 2020
School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, People's Republic of China.
5-Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) is a non-specific chloride channel blocker. Peritoneal adhesion is an inevitable complication of abdominal surgery and remains an important clinical problem, leading to chronic pain, intestinal obstruction, and female infertility. The aim of this study is to observe the effects of NPPB on peritoneal adhesions and uncover the underlying mechanism.
View Article and Find Full Text PDFJ Am Heart Assoc
October 2019
Background Atrial fibrillation often occurs in the setting of hypertension and associated atrial dilation with pathologically increased cardiomyocyte stretch. In the setting of atrial dilation, mechanoelectric feedback has been linked to the development of ectopic beats that trigger paroxysmal atrial fibrillation mainly originating from pulmonary veins (PVs). However, the precise mechanisms remain poorly understood.
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