Modulation of Voltage-Dependent K+ Channel Current in Vascular Smooth Muscle Cells from Rat Mesenteric Arteries

Modulation of Voltage-Dependent K+ Channel Current in Vascular Smooth Muscle Cells from Rat... Voltage-dependent K+ (Kv) channels were studied in smooth muscle cells (SMCs) freshly isolated from rat mesenteric arteries. A delayed outward rectifier Kv current (I K) with a weak voltage dependence was identified. The amplitude of I K, but not its inactivation kinetics, was inhibited by 4-aminopyridine (4-AP) (IC50, 5.1 ± 0.9 mm). The inhibitory effect of 4-AP was not use-dependent, and the unbinding of 4-AP from I K channels was complete in the absence of depolarization stimuli, suggesting the binding of 4-AP to the closed state of Kv channels. There was no change in the steady-state inactivation, but the steady-state activation curve of I K was shifted in the presence of 4-AP by +6 mV. Including 4-AP in pipette solution instantly inhibited I K upon the rupture of cell membrane, indicating that 4-AP bound to the inner mouth of Kv channel pores. Several Kv channel proteins encoding the native I K-type Kv channels, but not the transient outward A-type Kv channels, were identified. Among the identified I K-encoding gene transcripts, the expression of Kv1.5 was the most abundant. Our results elucidate the modulating mechanisms for the 4-AP-induced I K inhibition in rat mesenteric artery SMCs and suggest that the unique properties of Kv channels in these cells might be related to the heteromeric expression of the I K-encoding genes with Kv1.5 subunit playing an important role. The Journal of Membrane Biology Springer Journals

Modulation of Voltage-Dependent K+ Channel Current in Vascular Smooth Muscle Cells from Rat Mesenteric Arteries

Loading next page...
Copyright © Inc. by 2001 Springer-Verlag New York
Life Sciences; Biochemistry, general; Human Physiology
Publisher site
See Article on Publisher Site

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial