Channel activators regulate ATP-sensitive potassium channel (KIR6.1) expression in chick cardiomyocytes.
ATP-sensitive potassium channels (K(ATP)) are widely expressed and yet little is known about the mechanisms regulating their expression. Here we report that expression of chick heart Kir6.1 is regulated by channel activators. Activation of K(ATP) with either ATP depletion or pinacidil, up-regulated Kir6.1 mRNA 1.8- to 2.4-fold in cultured ventricular myocytes as measured by competitive PCR. Pinacidil treatment also increased Kir6.1 protein as detected using an antibody to Kir6.1. Glibenclamide, a K(ATP) inhibitor, completely blocked the pinacidil-induced increase in Kir6.1 levels. It appears that Kir6.1 is up-regulated by an unknown signal transduction pathway initiated by K(ATP) opening.
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Department of Biochemical Pharmacology, State University of New York at Buffalo, Amherst 14260, USA.
Halvorsen
S W
SW
D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002642:Chick Embryo; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000187:drug effects*; D005905:Glyburide / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D015151:Immunoblotting; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D020110:Pinacidil; D016133:Polymerase Chain Reaction; D015221:Potassium Channels / Q000187:drug effects / Q000235:genetics*; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction
D006146:Guanidines; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger; D020110:Pinacidil; D000255:Adenosine Triphosphate; D005905:Glyburide