Ion channels are important therapeutic targets for the treatment of a variety of conditions. Among ion channel blocking agents, use-dependent inhibitors can be especially effective therapeutic agents. Use dependence allows the selective inhibition of hyperactive neurons or tachycardiac myocytes, while minimizing effects on cells with normal activity. For voltage-gated channels, the use-dependent compounds typically bind to and inhibit a particular kinetic state that is induced by specific voltage changes. Drug discovery programs that focus on this class of drugs need to rank the use dependence of the compounds. A meaningful comparison among different molecules requires voltage clamp-based assays with continuous voltage control and compensation for or elimination of electrode drift-related effects. A method was developed based on automated electrophysiology in which voltage and frequency dependence of voltage-gated ion channel blockers can be compared using a protocol in which voltage error is compensated for in real time.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1089/adt.2006.4.57 | DOI Listing |
J Cardiovasc Pharmacol
January 2025
Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Positive inotropic responses upon administration of milrinone, an inhibitor of the phosphodiesterase enzyme (PDE), involve a well-pronounced positive chronotropic effect. Here we tested whether milrinone evokes this chronotropic response solely by PDE inhibition or by a concerted action that involve additional pharmacological targets. Milrinone stimulated increases in heart rate were studied in right atrial preparations of guinea pig in the presence or absence of inhibitors of putative ancillary molecular pathways or ion channels: i.
View Article and Find Full Text PDFJ Gen Physiol
March 2025
School of Medicine, Pharmacy and Biomedical Sciences, Faculty of Science & Health, University of Portsmouth, Portsmouth, UK.
Elhanafy et al. used Molecular Dynamics simulations and electrophysiology to show how identical mutations in the volgage sending domain of sodium channels can yield differential functional effects.
View Article and Find Full Text PDFMol Ecol
January 2025
Institute of Freshwater Research, Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences, Drottningholm, Sweden.
How genetic variation contributes to adaptation at different environments is a central focus in evolutionary biology. However, most free-living species still lack a comprehensive understanding of the primary molecular mechanisms of adaptation. Here, we characterised the targets of selection associated with drastically different aquatic environments-humic and clear water-in the common freshwater fish, Eurasian perch (Perca fluviatilis).
View Article and Find Full Text PDFFront Neural Circuits
January 2025
Department of Neurobiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
A strong repetitive stimulus can occasionally enhance axonal excitability, leading to the generation of afterdischarge. This afterdischarge outlasts the stimulus period and originates either from the physiological spike initiation site, typically the axon initial segment, or from ectopic sites for spike generation. One of the possible mechanisms underlying the stimulus-induced ectopic afterdischarge is the local depolarization due to accumulated potassium ions surrounding the axonal membranes of the distal portion.
View Article and Find Full Text PDFBiochemistry
January 2025
Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132, United States.
Glutamine synthetase (GS) is a ubiquitous enzyme central to nitrogen metabolism, catalyzing the ATP-dependent formation of glutamine from glutamate and ammonia. Positioned at the intersection of nitrogen metabolism with carbon metabolism, the activity of GS is subject to sophisticated regulation. While the intricate regulatory pathways that govern GS were established long ago, recent work has demonstrated that homologues are controlled by multiple distinct regulatory patterns, such as the metabolite induced oligomeric state formation in archaeal GS by 2-oxoglutarate.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!