Role of the sigma receptor in the inhibition of [3H]-noradrenaline uptake in brain synaptosomes and adrenal chromaffin cells.
1. Rat brain synaptosomes and cultured bovine adrenal chromaffin cells were used to monitor the inhibitory effects of phencyclidine (PCP) and sigma (sigma)-receptor ligands on the uptake of [3H]-noradrenaline ([3H]-NA). 2. A Na(+)-dependent high affinity uptake was observed in synaptosomes (30 degrees C) and chromaffin cells (37 degrees C) with Km of 0.22 and 0.56 microM and Vmax of 2.5 pmol min-1 mg-1 protein and 0.7 pmol min-1 per 10(6) cells, respectively. 3. PCP and haloperidol inhibited the high affinity uptake with IC50 of 0.17 and 0.42 microM, respectively in synaptosomes and 0.24 and 0.47 microM, respectively in adrenal chromaffin cells. 4. A close correlation (r = 0.96) was established between the ability of various PCP and sigma-receptor ligands to inhibit [3H]-NA uptake in both systems: PCP greater than TCP greater than haloperidol greater than 3-(+)-PPP greater than MK-801 greater than or equal to (-)-butaclamol greater than (+)-SKF-10047 greater than DTG. Spiperone and opioid receptor ligands were ineffective at 20 microM. 5. These results indicate that the central and peripheral inhibitory effects of PCP and sigma-receptor ligands on [3H]-NA uptake involves a receptor (sigma 1-like) which is distinct from that (PCP2) recognized for the inhibition of [3H]-dopamine uptake by PCP.
Rogers
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C
Department of Pharmacology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
Lemaire
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S
D000311:Adrenal Glands / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D002838:Chromaffin System / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010622:Phencyclidine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000502:physiology; D011957:Receptors, Opioid / Q000502:physiology*; D017478:Receptors, Phencyclidine; D017480:Receptors, sigma; D013574:Synaptosomes / Q000378:metabolism*
D017981:Receptors, Neurotransmitter; D011957:Receptors, Opioid; D017478:Receptors, Phencyclidine; D017480:Receptors, sigma; D010622:Phencyclidine; D009638:Norepinephrine