Effects of insulin on potassium currents of rat ventricular myocytes in streptozotocin diabetes.
Membrane currents of ventricular cardiomyocytes isolated from control, diabetic and insulin-treated diabetic Wistar rats have been measured using the whole cell configuration of the patch-clamp technique. Insulin restored the density of the 4-aminopyridine-sensitive early transient component of the calcium-independent outward potassium currents which decreased in diabetes. The inactivation rate of the transients increased in diabetes and was normalised by insulin. The late 4-aminopyridine-insensitive component of the outward currents showed the same diabetes- and insulin-related changes. This current could reflect the activation of the delayed rectifier channels although pharmacological identification of this component could not be achieved.
Magyar
J
J
Department of Physiology, University Medical School of Debrecen, Hungary.
Cseresnyés
Z
Z
Rusznák
Z
Z
Sipos
I
I
Szücs
G
G
Kovács
L
L
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D006352:Heart Ventricles / Q000187:drug effects / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D017136:Ion Transport / Q000187:drug effects; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D007328:Insulin; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D015761:4-Aminopyridine; D011188:Potassium; D002118:Calcium