A sigma-like binding site in rat pheochromocytoma (PC12) cells: decreased affinity for (+)-benzomorphans and lower molecular weight suggest a different sigma receptor form from that of guinea pig brain

Differentiation of σ ligand‐activated receptor subtypes that modulate NMDA‐evoked [3H]‐noradrenaline release in rat hippocampal slices

“…Two subtypes of ai receptors, termed a1 and ci2, have since been identified from binding studies and functional bioassays (Hellewell & Bowen, 1990;Walker et al, 1990;Quirion et al, 1992;Su & Junien, 1994). (+)-Pentazocine acts selectively on al whereas 1,3-di-(2-tolyl)guanidine (DTG) and haloperidol act on both al and ci2 receptors.…”

Purification and Characterization of the Human SR 31747A-binding Protein

“…However, unlike cyclosporin A, SR 31747A does not alter early cellular events, but rather interferes at steps further along the pathway leading to proliferation, most probably during the S phase (14). Multiple receptors have been described (8,(15)(16)(17)(18)(19). Sigma 1 designates a high affinity binding site, which is stereoselective for (ϩ)-optical enantiomers of pentazocine, SKF 10,047, and 3-(3-hydroxyphenyl)-N-(1-propyl)-piperidine (3-PPP).…”

Multiple σ binding sites in guinea‐pig and rat brain membranes: G‐protein interactions

“…Although a binding sites were originally thought to be a single entity, the current consensus is that two subtypes exist, rI and a2 (Bowen & Hellewell, 1988;Hellewell & Bowen, 1990;Knight et al, 1991a,b;Rothman et al, 1991;Quirion et al, 1992). Indeed, sophisticated computer assisted models of self and cross-displacement a ligand binding experiments have identified up to four binding sites (R-R4) for a ligands (Zhou & Musacchio, 1991;Klein & Musacchio, 1992).…”

“…Similarly, 3PPP selectively binds to a binding sites (Weber et al, 1986). Subsequent investigations of the binding profiles of these ligands have led investigators to suggest that there are two a sites; al and a2 (Hellewell & Bowen, 1990;Quirion et al, 1992). Other groups have sug-gested that as many as four binding sites (R1 -R4) are identifiable (Zhou & Musacchio, 1991).…”