| Autor: |
McKay, M. Craig, Worley III, Jennings F. |
| Předmět: |
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| Zdroj: |
American Journal of Physiology: Cell Physiology; Oct2001, Vol. 281 Issue 4, pC1277, 8p, 30 Graphs |
| Abstrakt: |
Linoleic acid both enhances activation and blocks Kv1.5 and Kv2.1 channels by two separate mechanisms. Am J Physiol Cell Physiol 281: C1277-C1284, 2001.—Linoleic acid (LA) had two effects on human Kv1.5 and Kv2.1 channels expressed in Chinese hamster ovary cells: an increase in the speed of current activation process (EC[sub 50] = 2.4 and 2.7 µM for Kv1.5 and Kv2.1, respectively) and current inhibition (IC[sub 50] = 6.6 and 7.4 for Kvl.5 and Kv2.1, respectively). LA affected the activation kinetics via two processes: a leftward shift in the instantaneous activation curves and an increase in the rate of current rise. Current inhibition by LA was time dependent but voltage independent. Hill slopes for plots of current inhibition (3.5 and 3.9 for Kvl.5 and Kv2.1, respectively) vs. dose of LA suggested that cooperativity was involved in the mechanism of current inhibition. A similar analysis of the effects of LA on current activation did not reveal cooperative interactions. The effects of LA were mediated from the external side of the channels, since addition of 10 µM LA to the patch pipette solution was without effect. Additionally, the methyl ester of LA was effective at enhancing peak current and promoting channel activation for Kvl.5 and Kv2.1 without inducing significant current inhibition. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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