To obtain an optimized T-type calcium channel blocker with reduced off-target hERG toxicity, we modified the structure of the original compound by introducing a zwitterion and reducing the basicity of the nitrogen. Among the structurally modified compounds we designed, compounds 5 and 6, which incorporate amides in place of the original compound's amines, most appreciably alleviated hERG toxicity while maintaining T-type calcium channel blocking activity. Notably, the benzimidazole amide 5 selectively blocked T-type calcium channels without inhibiting hERG (hERG/T-type⩾220) and L-type channels (L-type/T-type=96), and exhibited an excellent pharmacokinetic profile in rats.
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http://dx.doi.org/10.1016/j.bmcl.2013.12.078 | DOI Listing |
The Ca 3.2 isoform of T-type voltage-gated calcium channels plays a crucial role in regulating the excitability of nociceptive neurons; the endogenous molecules that modulate its activity, however, remain poorly understood. Here, we used serum proteomics and patch-clamp physiology to discover a novel peptide albumin (1-26) that facilitates channel gating by chelating trace metals that tonically inhibit Ca 3.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Fight Against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea; Global Excellence Center for Gene & Cell Therapy (GEC-GCT), Seoul National University Hospital, Seoul, Republic of Korea; Department of Biomedical Sciences & Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea; Institute of Reproductive Medicine and Population, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address:
Carboplatin resistance in retinoblastoma, an aggressive pediatric intraocular tumor, remains a major clinical challenge in treatment. This study elucidates the role of T-type calcium channels in carboplatin resistance using human retinoblastoma Y79 cells. We generated carboplatin-resistant Y79 (Y79CR) cells and characterized their electrophysiological properties.
View Article and Find Full Text PDFKorean J Physiol Pharmacol
January 2025
Department of Pharmacology, Catholic Kwandong University College of Medicine, Gangneung 25601, Korea.
Neurosteroids play an important role as endogenous neuromodulators that are locally produced in the central nervous system and rapidly change the excitability of neurons and the activation of microglial cells and astrocytes. Here we review the mechanisms of synthesis, metabolism, and actions of neurosteroids in the central nervous system. Neurosteroids are able to play a variety of roles in the central nervous system under physiological conditions by binding to membrane ion channels and receptors such as gamma-aminobutyric acid type A receptors, Nmethyl- D-aspartate receptors, L- and T-type calcium channels, and sigma-1 receptors.
View Article and Find Full Text PDFReprod Sci
January 2025
Department of Physiology, College of Graduate Studies, Midwestern University, Downers Grove, IL, 60515, USA.
The experience of pregnancy affects uterine function well beyond delivery. We previously demonstrated that the response to oxytocin is more robust in the uteri of proven breeder rats. This study investigates the contribution of T-type calcium channels (TTCCs) and L-type calcium channels (LTCCs) to the distinct response of virgin (V) and proven breeder (PB) rat uteri to oxytocin.
View Article and Find Full Text PDFCell Calcium
January 2025
Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557, USA. Electronic address:
Interstitial cells of Cajal in the plane of the myenteric plexus (ICC-MY) serve as electrical pacemakers in the stomach and small intestine. A similar population of cells is found in the colon, but these cells do not appear to generate regular slow wave potentials, as characteristic in more proximal gut regions. Ca handling mechanisms in ICC-MY of the mouse proximal colon were studied using confocal imaging of muscles from animals expressing GCaMP6f exclusively in ICC.
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