Regulation of transient outward K+ current in human atria involves G proteins.
The role of G protein in regulating the transient outward K+ current (I(to)) was examined by using isolated human atrial myocytes. When a nonhydrolyzable analogue of guanosine 5'-triphosphate (GTP gamma s) was introduced intracellularly, I(to) was irreversibly decreased and reached a new steady-state within 3 minutes. These results suggest that regulation of I(to) is similar to that of other K+ current in the heart and involves guanine nucleotide-binding proteins. This has important implications with respect to autonomic control of action potential duration in the human heart.
Le Grand
B
B
Laboratoire de Physiologie Cellulaire, Université Paris XI, Orsay, France.
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D004533:Egtazic Acid / Q000494:pharmacology; D004553:Electric Conductivity / Q000187:drug effects; D004594:Electrophysiology / Q000379:methods; D005260:Female; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006321:Heart / Q000502:physiology*; D006325:Heart Atria; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008875:Middle Aged; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D012433:Ryanodine / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
D015221:Potassium Channels; D012433:Ryanodine; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D004533:Egtazic Acid; D019204:GTP-Binding Proteins