Pyrimidine-2,4,6-triones are a new class of voltage-gated L-type Ca2+ channel activators.
Nat Commun 2014;
5:3897. [PMID:
24941892 PMCID:
PMC4083433 DOI:
10.1038/ncomms4897]
[Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/15/2014] [Indexed: 12/15/2022] Open
Abstract
Cav1.2 and Cav1.3 are the main L-type Ca2+ channel subtypes in the brain. Cav1.3 channels have recently been implicated in the pathogenesis of Parkinson’s disease. Therefore, Cav1.3-selective blockers are developed as promising neuroprotective drugs. We studied the pharmacological properties of a pyrimidine-2,4,6-trione derivative (1-(3-chlorophenethyl)-3-cyclopentylpyrimidine-2,4,6-(1H,3H,5H)-trione, Cp8) recently reported as the first highly selective Cav1.3 blocker. Here we show, in contrast to this previous study, that Cp8 reproducibly increases inward Ca2+ currents of Cav1.3 and Cav1.2 channels expressed in tsA-201 cells by slowing activation, inactivation and enhancement of tail currents. Similar effects are also observed for native Cav1.3 and Cav1.2 channels in mouse chromaffin cells, while non-L-type currents are unaffected. Evidence for a weak and non-selective inhibition of Cav1.3 and Cav1.2 currents is only observed in a minority of cells using Ba2+ as charge carrier. Therefore, our data identify pyrimidine-2,4,6-triones as Ca2+ channel activators.
Selective inhibitors of the L-type Ca2+ channel Cav1.3 are being developed as neuroprotective drugs. Here, Ortner et al. assess the pharmacological properties of a recently reported, selective Cav1.3 blocker and show that this agent is a Ca2+ channel activator.
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