Effects of phencyclidine on contractile forces of isolated rabbit papillary muscles.
Phencyclidine (PCP) (0.01-50 mumol.L-1) and its analogue, TCP (0.01-50 mumol.L-1) exhibited positive inotropic effects on electrically stimulated rabbit papillary muscle preparations. Dextrorphan (5 or 10 mumol.L-1) antagonized the actions of PCP in non-competitive manner (pD'2 = 5.25). This demonstrated the involvement of PCP receptors in the positive inotropic effects of PCP. By using high performance liquid chromatography with electrochemical detector (HPLC-ECD), an increase of DOPAC content was found in bath medium after PCP addition. Each of the dopamine receptor antagonists SCH23390, haloperidol and sulpiride (1 mumol.L-1) attenuated the maximal inotropic effects of PCP. These results suggest that PCP induces positive inotropic effects by increasing the release and/or blocking the uptake of dopamine.
Dai
J L
JL
Department of Neurobiology, Shanghai Medical University, China.
Xu
S F
SF
D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003917:Dextrorphan / Q000494:pharmacology; D005260:Female; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects / Q000502:physiology; D010622:Phencyclidine / Q000031:analogs & derivatives / Q000494:pharmacology*; D011817:Rabbits; D013268:Stimulation, Chemical; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D003917:Dextrorphan; D015102:3,4-Dihydroxyphenylacetic Acid; D013469:Sulpiride; C012058:tenocyclidine; D010622:Phencyclidine; D006220:Haloperidol