Astrocytes are a known 'sink' for brain methylmercury (MeHg) deposition. Yet, the significance of the preferential accumulation of MeHg within these cells is imprecisely defined. To determine whether MeHg in isotonic buffer has the potential to interfere with homeostatic functions, we measured its effect on astrocytic volume using an electrical impedance method [E.R. O'Connor, H.K. Kimelberg, C.R. Keese, I. Giaever, Electrical impedance method for measuring volume changes in astrocytes, Am. J. Physiol. 264 (1993) C471-C478.]. In addition, we have characterized the alterations in astrocytic ion permeability associated with exposure to this organometal. The results show that MeHg rapidly induces astrocytic swelling, and that this effect is secondary to increased astrocytic Na+ uptake. Furthermore, the effect of MeHg on astrocytic swelling is completely inhibited by amiloride, but not by SITS (4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid), furosemide, or bumetanide. Accordingly, increased cellular permeability to Na+ via the Na+/H+ antiporter is invoked as the primary mechanism of MeHg-induced astrocytic swelling.

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0006-8993(98)00399-0DOI Listing

Publication Analysis

Top Keywords

astrocytic swelling
16
na+/h+ antiporter
8
electrical impedance
8
impedance method
8
astrocytic
6
mehg
5
methylmercury-induced astrocytic
4
swelling
4
swelling associated
4
associated activation
4

Similar Publications

Neovascular age-related macular degeneration and diabetic macular edema are leading causes of vision-loss evoked by retinal neovascularization and vascular leakage. The glycoprotein microfibrillar-associated protein 4 (MFAP4) is an integrin αβ ligand present in the extracellular matrix. Single-cell transcriptomics reveal MFAP4 expression in cell-types in close proximity to vascular endothelial cells including choroidal vascular mural cells and retinal astrocytes and Müller cells.

View Article and Find Full Text PDF

Mogroside V ameliorates astrocyte inflammation induced by cerebral ischemia through suppressing TLR4/TRADD pathway.

Int Immunopharmacol

January 2025

Medical College of Guangxi University, Guangxi University, Nanning 530004, China; Fujian Maternity and Child Health Hospital, Fuzhou, 350001, China; Stem Cell Therapy Research Center, Fuzhou 350001, China.. Electronic address:

Inflammation and oxidative stress are pivotal factors in the onset and progression of secondary injury following cerebral ischemia-reperfusion (I/R). Mogroside V (MV), a primary active compound of Siraitia grosvenorii, exhibits significant anti-inflammatory and antioxidant properties. However, its specific effects in cerebral ischemia remain unclear.

View Article and Find Full Text PDF

Methionine sulfoximine (MSO) is a compound originally discovered as a byproduct of agene-based milled flour maturation. MSO irreversibly inhibits the astrocytic enzyme glutamine synthase (GS) but also interferes with the transport of glutamine (Gln) and of glutamate (Glu), and γ-aminobutyric acid (GABA) synthesized within the Glu/Gln-GABA cycle, in this way dysregulating neurotransmission balance in favor of excitation. No wonder that intraperitoneal administration of MSO has long been known to induce behavioral and/or electrographic seizures.

View Article and Find Full Text PDF

Thrombin-induced kynurenine 3-monooxygenase causes variations in the kynurenine pathway, leading to neurological deficits in a murine intracerebral hemorrhage model.

J Pharmacol Sci

February 2025

Department of Physical Chemistry for Bioactive Molecules, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292, Japan.

The purpose of the present study is to investigate changes in the kynurenine pathway after intracerebral hemorrhage (ICH) and its effects on ICH-induced injury. The exposure of a primary rat microglial culture to thrombin increased the mRNA level of kynurenine 3-monooxygenase (KMO), and this increase was attenuated by a p38 MAPK inhibitor. Thrombin also increased the protein level of KMO.

View Article and Find Full Text PDF

Traditional Chinese Medicine Borneol-Based Polymeric Micelles Intracerebral Drug Delivery System for Precisely Pathogenesis-Adaptive Treatment of Ischemic Stroke.

Adv Sci (Weinh)

January 2025

Frontiers Science Center for Deep Ocean Multispheres and Earth Systems, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education/Sanya Oceanographic Institution, Ocean University of China, Qingdao/Sanya, 266003/572024, China.

The scarcity of effective neuroprotective agents and the presence of blood-brain barrier (BBB)-mediated extremely inefficient intracerebral drug delivery are predominant obstacles to the treatment of cerebral ischemic stroke (CIS). Herein, ROS-responsive borneol-based amphiphilic polymeric NPs are constructed by using traditional Chinese medicine borneol as functional blocks that served as surface brain-targeting ligand, inner hydrophobic core for efficient drug loading of membrane-permeable calcium chelator BAPTA-AM, and neuroprotective structural component. In MCAO mice, the nanoformulation (polymer: 3.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!