In this study, the possible involvement of L-type voltage-operated calcium channels in the vasorelaxant effect of the flavonoid quercetin was investigated, using the isolated aortic rings from normal male rats. Addition of quercetin (0.1 µM-1 mM) caused a significant dose-dependent relaxation of noradrenaline (NA)- and KCl-preconstricted rings and nifedipine attenuated this response, especially...

L-type calcium channels play only a minor role in basal neurotransmitter release in brain neurons but contribute significantly after induction of plasticity. Very little is known about mechanisms that enable L-type calcium channel participation in neurotransmitter release. Here, using mouse primary cortical neurons, we found that inhibition of Erk1/2 (extracellular signal-regulated kinases 1 an...

Neuronal L-type calcium channels are essential for regulating activity-dependent gene expression, but they are thought to open too slowly to contribute to action potential-dependent calcium entry. A complication of studying native L-type channels is that they represent a minor fraction of the whole-cell calcium current in most neurons. Dihydropyridine antagonists are therefore widely used to es...

Extremely low-frequency electromagnetic fields (ELF-EMF) causes various biological effects through altering intracellular calcium homeostasis. The role of high voltage-gated (HVA) calcium channels in ELF-EMF induced effects has been extensively studied. However, the effect of ELF-EMF on low-voltage-gated (LVA) T-type calcium channels has not been reported. In this study, we test the effect of E...

The effects of riluzole, a neuroprotective drug, on high voltage-activated (HVA) calcium channels of rat dorsal root ganglion neurons were studied using the whole-cell patch-clamp technique. Riluzole inhibited HVA calcium channel currents in a dose-dependent, time-dependent and reversible manner. The apparent dissociation constants for riluzole inhibition of the transient and sustained componen...

In this study, the possible involvement of L-type voltage-operated calcium channels in the vasorelaxant effect of the flavonoid quercetin was investigated, using the isolated aortic rings from normal male rats. Addition of quercetin (0.1 µM-1 mM) caused a significant dose-dependent relaxation of noradrenaline (NA)- and KCl-preconstricted rings and nifedipine attenuated this response, especially...

At many central synapses, endocannabinoids released by postsynaptic cells inhibit neurotransmitter release by activating presynaptic cannabinoid receptors. The mechanisms underlying this important means of synaptic regulation are not fully understood. It has been shown at several synapses that endocannabinoids inhibit neurotransmitter release by reducing calcium influx into presynaptic terminal...

When an action potential enters a synaptic terminal, voltage-gated calcium channels open, allowing calcium ions to enter and promote synaptic vesicle release. How many vesicles are released depends on the number of release sites and the density and location of calcium channels. If channels are close to release sites, incoming ions quickly bind to vesicle-associated calcium sensors, and relative...

High-voltage-activated (HVA) calcium channels are known to be the primary source of calcium for glucose-stimulated insulin secretion. However, few studies have investigated how these channels can be regulated by chronically elevated levels of glucose. In the present study, we determined the level of expression of the four major HVA calcium channels (N-type, P/Q-type, L(C)-type, and L(D)-type) i...