Quinacrine decreases the slow inward current and force in guinea pig ventricular tissue.
In guinea pig isolated ventricular myocytes, quinacrine (40 microM) decreases the action potential amplitude and duration, and markedly decreases the slow inward current (Isi). A lower quinacrine concentration (20 microM) has similar but smaller effects. In guinea pig papillary muscles, quinacrine decreases contractile force reversibly. Thus, in myocardial fibers the decrease in Isi by quinacrine appears to predominate over the inhibition of Na-Ca exchange found in membrane vesicles.
Yang
L
L
Department of Physiology, State University of New York, Health Science Center, Brooklyn 11203.
Vassalle
M
M
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D005260:Female; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007474:Ion Exchange; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010210:Papillary Muscles / Q000187:drug effects; D011796:Quinacrine / Q000494:pharmacology*
D011796:Quinacrine