Early exposure to hypertonic solution strongly intensifies the effects of K+ channel opener, rilmakalim, in guinea pig ventricular myocytes.
We report here that early exposure of guinea pig ventricular myocytes to hypertonic solution (approximately 400 mOsm compared to 280 mOsm in isotonic solution) increased the potency of rilmakalim to evoke ATP-sensitive K+ current 10 times (pD2 = 7.44 +/- 0.11 compared to pD2 = 6.49 +/- 0.18 in isotonic solution) without changing Emax, and observed effect was completely reversed by glibenclamide at 1 microM.
Kocić
Ivan
I
Department of Cardiovascular Diseases, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan. ikocic@amedec.amg.gda.pl
Hirano
Yuji
Y
Hiraoka
Masayasu
M
D000255:Adenosine Triphosphate / Q000378:metabolism / Q000502:physiology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D002839:Chromans / Q000494:pharmacology*; D004553:Electric Conductivity; D005260:Female; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology; D066298:In Vitro Techniques; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D011759:Pyrrolidines / Q000494:pharmacology*; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage / Q000494:pharmacology*
D000889:Anti-Arrhythmia Agents; D002839:Chromans; D015221:Potassium Channels; D011759:Pyrrolidines; D012462:Saline Solution, Hypertonic; C075012:rilmakalim; D000255:Adenosine Triphosphate