The primary mode of action of local anesthetics is through sodium channel and axonal conduction blockade. Local anesthetics have also extensive effects on pre-synaptic calcium channels that must function to stimulate the release of neurotransmitters. Thus, interference with calcium channel conductance may enhance spinal anesthesia with local anesthetics. The present study was designed to invest...

The primary mode of action of local anesthetics is through sodium channel and axonal conduction blockade. Local anesthetics have also extensive effects on pre-synaptic calcium channels that must function to stimulate the release of neurotransmitters. Thus, interference with calcium channel conductance may enhance spinal anesthesia with local anesthetics. The present study was designed to invest...

Calcium channels play dual roles in cell signaling by promoting membrane depolarization and allowing entry of calcium ions. Patch-clamp recordings of calcium and calcium-dependent currents from the soma of Xenopus spinal neurons indicate key functional differences from those of presynaptic terminals. Both terminals and somas exhibit prominent high-voltage-activated (HVA) calcium current, but on...

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...

The developmental regulation of the N-type calcium channel during synaptogenesis was studied using cultured rat hippocampal neurons to elucidate the roles of extrinsic versus intrinsic cues in the expression and distribution of this channel. Prior to synapse formation, alpha1B and beta3 subunits of the N-type calcium channel were distributed diffusely throughout neurites, growth cones, and soma...

the protective effect of a l-type calcium channel blocker, nimodipine, on cell injury induced by oxygen-glucose deprivation (ogd) in pc12 cells was investigated. pc12 cells were exposed to in-vitro oxygen-glucose deprivation (30 minutes and 60 minutes respectively) in the presence or absence of nimodipine (10mm/l) in three different time schedules (pre-24h, pre-3h and concurrently). cellular vi...

In wild-type Caenorhabditis elegans, the synapse from motor neuron M4 to pharyngeal terminal bulb (TB) muscles is silent, and the muscles are instead excited by gap junction connections from adjacent muscles. An eat-5 innexin mutant lacking this electrical connection has few TB contractions and is unable to grow well on certain foods. We showed previously that this defect can be overcome by act...

We have synthesized a novel series of 18 dialkyl 1,4-dihydro-4-(2'alkoxy-6'-pentadecylphenyl)-2,6-dimethyl-3,5 pyridine dicarboxylates from anacardic acid, a natural compound found in cashew nut shells, and investigated their blocking action on L- and T-type calcium channels transiently expressed in tSA-201 cells. The IC(50) values for L-type calcium channel block obtained with the series range...

Hydrogen sulfide (H(2)S) is a novel gasotransmitter that inhibits L-type calcium currents (I (Ca, L)). However, the underlying molecular mechanisms are unclear. In particular, the targeting site in the L-type calcium channel where H(2)S functions remains unknown. The study was designed to investigate if the sulfhydryl group could be the possible targeting site in the L-type calcium channel in r...