of the dissertation ii

The known effects of calcium channel blockers on various aspects of potassium homeostasis are reviewed. Regulation of potassium homeostasis requires both renal and external handling mechanisms. Signaling by calcium appears to mediate both of these. Calcium channels have been identified in adrenal glomerulosa cells, and cellular calcium entry has been demonstrated in vitro to be necessary for th...

zinc is a substance that regulates neural excitability by binding whit sodium channel and potassium channel. the efficiency of free zinc ion, make down the neural survival rate, reduced the peak amplitude of na+ and make depolarization na channel, increased the peak amplitude of transition outward k+ currents and delayed rectifier. also it is an effective blocker of one subtype of tetrodoxine (...

PURPOSE In addition to photoreceptor degeneration, excessive light causes degenerative alterations in the inner retina and ganglion cell death. A disturbance in osmohomeostasis may be one causative factor for the alterations in the inner retina. Because Müller cells mediate inner retinal osmohomeostasis (mainly through channel-mediated transport of potassium ions and water), the authors investi...

The development of electrical excitability involves complex coordinated changes in ion channel activity. Part of this coordination appears to be due to the fact that the expression of some channels is dependent on electrical activity mediated by other channel types. For example, we have previously shown that normal potassium current development in embryonic skeletal muscle cells of the frog Xen...

Episodic ataxia type 1 (EA1) is a rare autosomal dominant disorder characterized by brief episodes of ataxia associated with continuous interattack myokymia. Point mutations in the human voltage-gated potassium channel (Kv1.1) gene on chromosome 12p13 have recently been shown to associate with EA1. A Scottish family with EA1 harbouring a novel mutation in this gene is reported. Of the five affe...

An intermediate conductance calcium-activated potassium channel, hIK1, was cloned from human pancreas. The predicted amino acid sequence is related to, but distinct from, the small conductance calcium-activated potassium channel subfamily, which is approximately 50% conserved. hIK1 mRNA was detected in peripheral tissues but not in brain. Expression of hIK1 in Xenopus oocytes gave rise to inwar...

Potassium channels in the apical and basolateral membranes of tubule cells serve several important functions. They contribute to the generation of the cell-negative potential, mediate volume reductions following cell swelling and play a key role in secretion of potassium in both the thick ascending limb of Henle's loop and principal tubule cells of the initial and cortical collecting tubules. S...

AIM To examine the effect of BmTx3B, a novel short-chain peptide isolated from the venom of Asian scorpion Buthus martensi Karsch, on voltage-gated potassium channels. METHODS Two types of voltage-dependent potassium currents were recorded from dissociated hippocampal neurons of neonatal rat in whole-cell voltage-clamp mode, and separated based upon their kinetic properties. RESULTS BmTx3B ...

Significance AMPA-type glutamate receptors (AMPARs) make the final step in a relay of excitability from one brain cell to another. The receptor contains an integral ion channel, which, when opened by neurotransmitter, permits sodium and other cations cross membrane. We investigated permeation sodium, potassium, cesium at atomistic level using computational molecular dynamics approach obtained t...