Gonadotrophs are basophilic cells of the anterior pituitary gland specialized to secrete gonadotropins in response to elevation in intracellular calcium concentration. These cells fire action potentials (APs) spontaneously, coupled with voltage-gated calcium influx of insufficient amplitude to trigger gonadotropin release. The spontaneous excitability of gonadotrophs reflects the expression of ...

213 Abstract: The aim of the present study was to investigate the role of the L-type voltage dependent Ca2+ channel blocker, nimodipine, in kainate induced toxicity in retinal ganglion cells of mice. Kainate in 10mg/kg was administered intraperitoneally following the vehicle or nimodipine. Nimodipine, 45 minutes prior to kainate in 10, 15, 25, 50, 100 and 250 mg/kg doses was administered intrap...

Chromaffin cells express N-type calcium channels identified on the basis of their high sensitivity to block by v-conotoxin GVIA (v-CgTx GVIA). In contrast to neuronal N-type calcium currents that inactivate during long depolarizations and that require negative holding potentials to remove inactivation, many chromaffin cells exhibit N-type calcium channel currents that show little inactivation d...

In the early neonatal period activation of GABAB receptors attenuates calcium current through N-type calcium channels while enhancing current through L-type calcium channels in rat hippocampal neurons. The attenuation of N-type calcium current has been previously demonstrated to occur through direct interactions of the βγ subunits of Gi/o G-proteins, but the signal transduction pathway for the ...

OBJECTIVE To examine the hypothesis that hydrogen sulfide (H2S) regulates the colonic motility by modulating both L-type voltage-dependent calcium channels and large conductance Ca2+-activated K+ (BKCa) channels. METHODS Immunohistochemistry was performed on rat colonic samples to investigate the localization of the H2S-producing enzymes cystathionine-β-synthase (CBS) and cystathionine-γ-lyas...

Smoking is a widespread health problem. Because the nicotine withdrawal syndrome is a major contributor to continued smoking and relapse, it is important to understand the molecular and behavioral mechanisms of nicotine withdrawal to generate more effective smoking cessation therapies. Studies suggest a role for calcium-dependent mechanisms, such as L-type calcium channels and calcium/calmoduli...

T-type calcium channels represent a key pathway for Ca(2+) entry near the resting membrane potential. Increasing evidence supports a unique role of these channels in fast and low-threshold exocytosis in an action potential-independent manner, but the underlying molecular mechanisms have remained unknown. Here, we report the existence of a syntaxin-1A/Ca(v)3.2 T-type calcium channel signaling co...