Effect of centhaquine on spontaneous and evoked norepinephrine release from isolated perfused rabbit heart

1-[Bis(2-quinolyl)-ethyl]-4-m-tolylpiperazine (centhaquine), a centrally acting hypotensive agent, was studied for its effect on spontaneous and evoked release of norepinephrine (NE) from the rabbit heart. Spontaneous release of NE as well as its release evoked by potassium chloride (81 X 10(-3) mol/l), tyramine hydrochloride (2.88 X 10(-5) mol/l), dimethyl phenyl piperazinium iodide (DMPP, 3.18 X 10(-5) mol/l), acetylcholine chloride (1 X 10(-4) mol/l) and amphetamine sulfate (7.48 X 10(-5) mol/l) from isolated perfused rabbit heart was studied. Centhaquine (0.1, 1.0 and 10.0 micrograms/ml) caused an initial increase followed by inhibition of spontaneous NE output. It also significantly inhibited the NE release evoked by KCl, DMPP and acetylcholine but not tyramine and amphetamine evoked release. It is concluded that centhaquine predominantly inhibits the neuronal NE release.