Normetazocine analogue as opioid antagonist.
skf 10047 hydrochloride is a prototypical σ1 receptor agonist. behaviorally active in animal models of memory and stress. it has been fully demonstrated that σ binding sites are distinct from phencyclidine binding sites on the nmda receptor-ion channel complex, which has investigated extensively the functional role of σ receptors in the central nervous system [1,2].
Selective σ1 receptor agonist.
the effects of the stereoisomers of n-allylnormetazocine (skf-10,047) were compared in rats on the hippocampal cholinergic functions. a putative σ1 receptor agonist, (+)-skf-10,047, increased hippocampal extracellular acetylcholine level as well as anti-amnesic effect against scopolamine-induced memory dysfunctions in rats. haloperidol, a putative σ1 receptor antagonist reversed these phenomena which were not produced by (-)-skf-10,047. such stereoselectivity and antagonism imply σ1 receptors involved in these (+)-skf-10,047-stimulated hippocampal cholinergic functions [2].
(+)-skf-10,047 and dextromethorphan, being co-administered with phenytoin (10 mg/kg, an anticonvulsant drug), decreased conditioned fear stress with low doses (4 and 20 mg/kg, respectively). the effects were antagonized by the σ receptor antagonists, ne-100 and bmy-14802. furthermore, the effects of (+)-skf-10,047 or dextromethorphan plus phenytoin were inhibited by the dopamine d1 receptor antagonist (sch 23390) and the dopamine d2 receptor antagonist ((-)-sulpiride), and they were also decreased by 6-hydroxydopamine-induced lesions of dopaminergic neurons. the ameliorating effects of (+)-skf-10,047 and dextromethorphan on condition of fear stress using high doses (5 and 30 mg/kg, respectively) were also inhibited by both the dopamine receptor antagonists [3].
[1] walker jm, bowen wd, walker fo, matsumoto rr, de costa b, rice kc. sigma receptors: biology and function. pharmacol rev. 1990 dec;42(4):355-402.
[2] matsuno k, senda t, kobayashi t, mita s. involvement of sigma 1 receptor in (+)-n-allylnormetazocine-stimulated hippocampal cholinergic functions in rats. brain res. 1995 sep 4; 690 (2): 200-6.
[3]. kamei h, kameyama t, nabeshima t. (+)-skf-10,047 and dextromethorphan ameliorate conditioned fear stress via dopaminergic systems linked to phenytoin-regulated sigma 1 sites. eur j pharmacol. 1996 aug 8;309(2):149-58.
