ion channels are responsible for control of cell function in excitable tissues such as heart and brain and also in organs and tissues traditionally thought to be non- excitable including liver and epithelium. in the present research, the effect of lead (pb2+) on ca2+ -dependent action potential and currents was studied in f77 neuronal soma membrane of helix aspersa. for this purpose, action pot...

Voltage-dependent Ca2+ channels contribute to neurotransmitter release, integration of synaptic information, and gene regulation within neurons. Thus understanding where diverse Ca2+ channels are expressed is an important step toward understanding neuronal function within a network. Drosophila provides a useful model for exploring the function of voltage-dependent Ca2+ channels in an intact sys...

Nicotinic acid adenine dinucleotide phosphate (NAADP) is capable of inducing global Ca2+ increases via a lysosome-associated mechanism, but the mechanism mediating NAADP-induced intracellular Ca2+ release remains unclear. The present study reconstituted and characterized a lysosomal NAADP-sensitive Ca2+ release channel using purified lysosomes from rat liver. Furthermore, the identity of lysoso...

t'a" channels from lipid and proteolipid fractions of oisplat in-sensitive and cisplatin-resistant cells were reconstituted and characterized in bilayer lipid membranes formed at the tips of patch-clamp micropipets. The characteristics of the Ca2* channels were typical for the endoplasmic reticulum membrane channel activity. They had a relatively large unit conductance and were modified by typi...

Transient receptor potential (TRP) mucolipins (TRPMLs), encoded by the MCOLN genes, are patho-physiologically relevant endo-lysosomal ion channels crucial for membrane trafficking. Several lines of evidence suggest that TRPMLs mediate localised Ca2+ release but their role in Ca2+ signalling is not clear. Here, we show that activation of endogenous and recombinant TRPMLs with synthetic agonists ...

N-type Ca2+ channels located on presynaptic nerve terminals regulate neurotransmitter release, including that from the spinal terminations of primary afferent nociceptors. Pharmacological and ion-channel gene knockdown approaches in animals have revealed N-type Ca2+ channels to be particularly attractive molecular targets for the discovery and development of new analgesic drugs. In recent years...

With the aim of characterizing the functional and pharmacological properties of the different voltage-dependent Ca2+ channels expressed in a given type of CNS neuron, we obtained single Ca2+ channel recordings from rat cerebellar granule cells in primary culture. Our data show that three novel classes of voltage-dependent Ca2+ channels are coexpressed in cerebellar granule cells. They are pharm...

1. Intracellular recordings, in conjunction with fura-2 fluorescence imaging, were used to evaluate the contribution of the different Ca2+ channel subtypes to the Ca2+ influx induced by back-propagating trains of action potentials. High-threshold channels contributed mainly to Ca2+ influx in pyramidal cell somata and proximal dendrites, whereas low-threshold and other Ni(2+)-sensitive channels ...

The intracellular calcium ions (Ca2+) act as second messenger to regulate gene transcription, cell proliferation, migration and death. Accumulating evidences have demonstrated that intracellular Ca2+ homeostasis is altered in cancer cells and the alteration is involved in tumor initiation, angiogenesis, progression and metastasis. Targeting derailed Ca2+ signaling for cancer therapy has become ...

Store-operated channels (SOC) and store-operated Ca2+ entry are known to play a major role in agonist-induced constriction of smooth muscle cells (SMC) in conduit vessels. In microvessels the role of SOC remains uncertain, in as much as voltage-gated L-type Ca2+ (Ca2+L) channels are thought to be fully responsible for agonist-induced Ca2+ influx and vasoconstriction. We present evidence that SO...