Phencyclidine blocks histamine H3-receptors in rat brain.
Phencyclidine (PCP) was examined for its ability to modulate histamine release from rat brain slices labeled with L-[3H]histidine. PCP failed to mimic but completely reversed the autoinhibitory effect of histamine at H3-receptors with an apparent Ki value of 13 +/- 3 microM. A direct interaction of PCP with H3-autoreceptors rather than PCP or sigma receptor sites was confirmed by binding studies. PCP inhibited the binding of [3H](R)alpha-methylhistamine to H3-receptor sites in rat cerebral membranes with a Ki value of 25 +/- 2 microM. It is concluded that PCP is a H3-receptor antagonist of moderate potency.
Arrang
J M
JM
Unité de Neurobiologie et Pharmacologie (U. 109) de l'INSERM, Paris, France.
Defontaine
N
N
Schwartz
J C
JC
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D006632:Histamine / Q000378:metabolism*; D066298:In Vitro Techniques; D010622:Phencyclidine / Q000494:pharmacology*; D051381:Rats; D011968:Receptors, Histamine / Q000187:drug effects*; D018100:Receptors, Histamine H3
D011968:Receptors, Histamine; D018100:Receptors, Histamine H3; D006632:Histamine; D010622:Phencyclidine