Inhibition of myocardial inward rectifier potassium current by propylbutyldopamine.
OBJECTIVE
To study the effects of propylbutyldopamine (PBDA) on the inward rectifier potassium current (Ik1).


METHODS
The quasi-steady state current-voltage relationship from the isolated guinea pig ventricular cells were measured using whole-cell patch-clamp techniques with a slow ramp depolarization (8 mV.s-1).


RESULTS
PBDA 5, 50, and 100 mumol.L-1 concentration-dependently reduced the inward rectifier potassium current. PBDA blocked Ik1 in guinea pig ventricular cells. The effect of PBDA was not blocked by the selective dopamine D2-receptor blocker, domperidone.


CONCLUSIONS
PBDA inhibited Ik1 directly, independent of the dopamine D2-receptor.
Dun
W
W
Department of Physiology, Shanxi Medical University, Taiyuan, China.
Zhao
R R
RR
Li
J G
JG
Wu
B W
BW
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects; D002469:Cell Separation; D004294:Domperidone / Q000494:pharmacology; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology; D006168:Guinea Pigs; D009206:Myocardium / Q000166:cytology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects*
D015220:Calcium Channels; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D015221:Potassium Channels; D004294:Domperidone; C016080:N-n-propyl-N-n-butyl-beta-dopamine; D004298:Dopamine