Abstract
In the present study, the effects of rutaecarpine on ionic currents of NG108-15 neuronal cells were studied. Rutaecarpine (2-100 £gM) suppressed the amplitude of voltage-dependent K+ outward current (IK(DR)) in a concentration-dependent manner. The IC50 value for rutaecarpine-induced inhibition of IK was 11£gM. However, rutaecarpine (20 £gM) had little effect on L-type Ca2+ current. IK(DR) present in these cells is sensitive to the inhibition by quinidine and dendrotoxin, yet not by E-4031. Rutaecarpine enhanced the rate and extent of IK(DR) inactivation, although it had no effect on the initial activation phase of IK(DR). Recovery from block by rutaecarpine (5 £gM) was fitted by a single exponential with a value of 2.87 s. Cell-attached single-channel recordings revealed that rutaecarpine decreased channel activity over the length of the test potential without altering single-channel amplitude. With the aid of binding scheme, a quantitative description of the actions of rutaecarpine on IK(DR) was provided. Under current-clamp configuration, rutaecarpine also prolonged action potential duration in NG108-15 cells without altering other variables of the action potential. The results clearly show that rutaecarpine is a blocker of the KDR channel. The increase in action potential duration induced by rutaecarpine can be
explained mainly by its blocking effects on IK(DR).
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0704102-153004 |
| Date | 04 July 2002 |
| Creators | Lin, Pei-Hsuan |
| Contributors | Chung-Ren Jan, Sheng-Nan Wu, Hung-Tu Huang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0704102-153004 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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