[3H]Imipramine is accumulated but not released from slices of the rabbit caudate and hypothalamus.
Slices of rabbit caudate and hypothalamus take up and accumulate [3H]imipramine. In superfused slices of both structures electrical stimulation or exposure to tyramine failed to release recently taken up [3H]imipramine. Depolarization by exposure to 30--60 mM-potassium caused only a small release of [3H]imipramine that was not concentration-dependent. The release of [3H]imipramine by high potassium was independent of the presence of calcium ions in the superfusion medium. These results contrasted with those obtained for the release of [3H]dopamine from the caudate and [3H]noradrenaline from the hypothalamus, where tyramine, electrical stimulation, and high potassium caused a significant release of the labeled neurotransmitters. The release of [3H]dopamine from the caudate and [3H]noradrenaline from the hypothalamus elicited by electrical stimulation or high potassium was entirely calcium-dependent. It is concluded that [3H]imipramine is taken up into the two brain regions and is accumulated in a nonvesicular site from which it is not released by calcium-dependent depolarizing stimuli.
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002421:Caudate Nucleus / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D004558:Electric Stimulation; D007031:Hypothalamus / Q000378:metabolism*; D007099:Imipramine / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains
D000661:Amphetamine; D007099:Imipramine; D011188:Potassium; D002118:Calcium; D004298:Dopamine; D009638:Norepinephrine