Rutaecarpine-induced block of delayed rectifier K+ current in NG108-15 neuronal cells. 2001

S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
Department of Medical Education and Research, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, 813, Kaohsiung, Taiwan. snwu@isca.vghks.gov.tw

The effects of rutaecarpine on ionic currents of NG108-15 neuronal cells were investigated in this study. Rutaecarpine (2-100 microM) suppressed the amplitude of delayed rectifier K+ current (I(K(DR))) in a concentration-dependent manner. The IC50 value for rutaecarpine-induced inhibition of I(K(DR)) was 11 microM. I(K(DR)) present in these cells is sensitive to the inhibition by quinidine and dendrotoxin, yet not by E-4031. The presence of rutaecarpine enhanced the rate and extent of I(K(DR)) inactivation, although it had no effect on the initial activation phase of I(K(DR)). Recovery from block by rutaecarpine (5 microM) was fitted by a single exponential with a value of 2.87 s. Crossover of tail currents in the presence of rutaecarpine was also observed. Cell-attached single-channel recordings revealed that rutaecarpine decreased channel activity, but it did not alter single-channel amplitude. With the aid of the binding scheme, a quantitative description of the rutaecarpine actions on I(K(DR)) was provided. However, rutaecarpine (20 microM) had no effect on L-type Ca2+ current. Under current-clamp configuration, rutaecarpine prolonged action potential duration in NG108-15 cells. These results show that rutaecarpine is a blocker of the K(DR) channel. The increase in action potential duration induced by rutaecarpine can be explained mainly by its blocking actions on I(K(DR)).

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D008564 Membrane Potentials The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009474 Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011799 Quinazolines A group of aromatic heterocyclic compounds that contain a bicyclic structure with two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring. Quinazoline
D004305 Dose-Response Relationship, Drug The relationship between the dose of an administered drug and the response of the organism to the drug. Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D000200 Action Potentials Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli. Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000470 Alkaloids Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed) Alkaloid,Plant Alkaloid,Plant Alkaloids,Alkaloid, Plant,Alkaloids, Plant
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D014407 Tumor Cells, Cultured Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely. Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D014665 Vasodilator Agents Drugs used to cause dilation of the blood vessels. Vasoactive Antagonists,Vasodilator,Vasodilator Agent,Vasodilator Drug,Vasorelaxant,Vasodilator Drugs,Vasodilators,Vasorelaxants,Agent, Vasodilator,Agents, Vasodilator,Antagonists, Vasoactive,Drug, Vasodilator,Drugs, Vasodilator

Related Publications

S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
October 2006, European journal of pain (London, England),
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
January 1997, Journal of molecular and cellular cardiology,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
March 1997, Brain research,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
February 2006, Journal of neurophysiology,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
March 2000, Neuroscience research,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
September 1996, Neuroreport,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
November 2009, Glia,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
July 2003, Neurobiology of disease,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
November 2003, British journal of pharmacology,
S N Wu, and Y K Lo, and H Chen, and H F Li, and H T Chiang
August 1995, The American journal of physiology,
Copied contents to your clipboard!