Anorexic effect of K+ channel blockade in mesenteric arterial smooth muscle and intestinal epithelial cells

S. S. McDaniel, O. Platoshyn, Y. Yu, M. Sweeney, V. A. Miriel, V. A. Golovina, S. Krick, B. R. Lapp, J. Y. Wang, J. X.J. Yuan

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

Activity of voltage-gated K+ (Kv) channels controls membrane potential (Em). Membrane depolarization due to blockade of K+ channels in mesenteric artery smooth muscle cells (MASMC) should increase cytoplasmic free Ca2+ concentration ([Ca2+]cyt) and cause vasoconstriction, which may subsequently reduce the mesenteric blood flow and inhibit the transportation of absorbed nutrients to the liver and adipose tissue. In this study, we characterized and compared the electrophysiological properties and molecular identities of Kv channels and examined the role of Kv channel function in regulating Em in MASMC and intestinal epithelial cells (IEC). MASMC and IEC functionally expressed multiple Kv channel α- and β-subunits (Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5, Kv2.1, Kv4.3, and Kv9.3, as well as Kvβ1.1, Kvβ2.1, and Kvβ3), but only MASMC expressed voltage-dependent Ca2+ channels. The current density and the activation and inactivation kinetics of whole cell Kv currents were similar in MASMC and IEC. Extracellular application of 4-aminopyridine (4-AP), a Kvchannel blocker, reduced whole cell Kv currents and caused Em depolarization in both MASMC and IEC. The 4-AP-induced Em depolarization increased [Ca2+]cyt in MASMC and caused mesenteric vasoconstriction. Furthermore, ingestion of 4-AP significantly reduced the weight gain in rats. These results suggest that MASMC and IEC express multiple Kv channel α- and β-subunits. The function of these Kv channels plays an important role in controlling Em. The membrane depolarization-mediated increase in [Ca2+]cyt in MASMC and mesenteric vasoconstriction may inhibit transportation of absorbed nutrients via mesenteric circulation and limit weight gain.

Original languageEnglish (US)
Pages (from-to)2322-2333
Number of pages12
JournalJournal of Applied Physiology
Volume91
Issue number5
DOIs
StatePublished - 2001

Keywords

  • Membrane potential
  • Sodium-dependent glucose symport
  • Voltage-gated potassium channel

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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    McDaniel, S. S., Platoshyn, O., Yu, Y., Sweeney, M., Miriel, V. A., Golovina, V. A., Krick, S., Lapp, B. R., Wang, J. Y., & Yuan, J. X. J. (2001). Anorexic effect of K+ channel blockade in mesenteric arterial smooth muscle and intestinal epithelial cells. Journal of Applied Physiology, 91(5), 2322-2333. https://doi.org/10.1152/jappl.2001.91.5.2322