Dihydropyridine Action on Voltage-dependent Potassium Channels Expressed in Xenopus Oocytes
Open Access
- 1 February 1997
- journal article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 109 (2) , 169-180
- https://doi.org/10.1085/jgp.109.2.169
Abstract
Dihydropyridines (DHPs) are well known for their effects on L-type voltage-dependent Ca2+ channels. However, these drugs also affect other voltage-dependent ion channels, including Shaker K+ channels. We examined the effects of DHPs on the Shaker K+ channels expressed in Xenopus oocytes. Intracellular applications of DHPs quickly and reversibly induced apparent inactivation in the Shaker K+ mutant channels with disrupted N- and C-type inactivation. We found that DHPs interact with the open state of the channel as evidenced by the decreased mean open time. The DHPs effects are voltage-dependent, becoming more effective with hyperpolarization. A model which involves binding of two DHP molecules to the channel is consistent with the results obtained in our experiments.Keywords
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