Expression of voltage-dependent K(+) channel genes in mesenteric artery smooth muscle cells.
Molecular basis of native voltage-dependent K(+) (Kv) channels in smooth muscle cells (SMCs) from rat mesenteric arteries was investigated. The whole cell patch-clamp study revealed that a 4-aminopyridine-sensitive delayed rectifier K(+) current (I(K)) was the predominant K(+) conductance in these cells. A systematic screening of the expression of 18 Kv channel genes using RT-PCR technique showed that six I(K)-encoding genes (Kv1.2, Kv1.3, Kv1.5, Kv2.1, Kv2.2, and Kv3.2) were expressed in mesenteric artery. Although no transient outward Kv currents (I(A)) were recorded in the studied SMCs, transcripts of multiple I(A)-encoding genes, including Kv1.4, Kv3.3, Kv3.4, Kv4.1, Kv4.2, and Kv4.3 as well as I(A)-facilitating Kv beta-subunits (Kvbeta1, Kvbeta2, and Kvbeta3), were detected in mesenteric arteries. Western blot analysis demonstrated that four I(K)-related Kv channel proteins (Kv1.2, Kv1. 3, Kv1.5, and Kv2.1) were detected in mesenteric artery tissues. The presence of Kv1.2, Kv1.3, Kv1.5, and Kv2.1 channel proteins in isolated SMCs was further confirmed by immunocytochemistry study. Our results suggest that the native I(K) in rat mesenteric artery SMCs might be generated by heteromultimerization of Kv genes.
Xu
C
C
Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E5.
Lu
Y
Y
Tang
G
G
Wang
R
R
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry; D015342:DNA Probes; D051668:Delayed Rectifier Potassium Channels; D004558:Electric Stimulation; D051638:Ether-A-Go-Go Potassium Channels; D015870:Gene Expression / Q000502:physiology; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D051664:Kv1.3 Potassium Channel; D051665:Kv1.4 Potassium Channel; D051666:Kv1.5 Potassium Channel; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008638:Mesenteric Arteries / Q000737:chemistry* / Q000166:cytology / Q000294:innervation; D009131:Muscle, Smooth, Vascular / Q000737:chemistry* / Q000166:cytology / Q000294:innervation; D009474:Neurons / Q000737:chemistry / Q000502:physiology; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000032:analysis* / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051669:Shab Potassium Channels; D051672:Shal Potassium Channels; D051670:Shaw Potassium Channels; D013564:Sympathetic Nervous System / Q000737:chemistry / Q000166:cytology; D019789:Tetraethylammonium / Q000494:pharmacology
D015342:DNA Probes; D051668:Delayed Rectifier Potassium Channels; D051638:Ether-A-Go-Go Potassium Channels; C496975:Kcna3 protein, rat; C496979:Kcna4 protein, rat; C496983:Kcna5 protein, rat; C496991:Kcnb1 protein, rat; C496994:Kcnb2 protein, rat; C484184:Kcnc3 protein, rat; C492014:Kcnc4 protein, rat; C497017:Kcnd1 protein, rat; C497020:Kcnd2 protein, rat; C497023:Kcnd3 protein, rat; C109501:Kcnh7 protein, rat; D051664:Kv1.3 Potassium Channel; D051665:Kv1.4 Potassium Channel; D051666:Kv1.5 Potassium Channel; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; D051669:Shab Potassium Channels; D051672:Shal Potassium Channels; D051670:Shaw Potassium Channels; D019789:Tetraethylammonium; D015761:4-Aminopyridine