Characterization of [3H][2-D-penicillamine, 5-D-penicillamine]-enkephalin binding to delta opiate receptors in the rat brain and neuroblastoma--glioma hybrid cell line (NG 108-15).
Specific binding properties of the tritium-labeled delta opiate receptor agonist [3H][2-D-penicillamine, 5-D-penicillamine]enkephalin [( 3H][D-Pen2, D-Pen5]enkephalin) were characterized in the rat brain and in a mouse neuroblastoma-rat glioma hybrid cell line (NG 108-15). Saturation isotherms of [3H][D-Pen2, D-Pen5]enkephalin binding to rat brain and NG 108-15 membranes gave apparent Kd values of 1-6 nM. These values are in good agreement with the Kd value obtained from the kinetic studies. The Bmax value in NG 108-15 membranes was 235.3 fmol/mg of protein. An apparent regional distribution of [3H][D-Pen2, D-Pen5]enkephalin binding was observed in the rat brain. A number of enkephalin analogues inhibited [3H][D-Pen2, D-Pen5]enkephalin binding with high affinity (IC50 values of 0.5-5.0 nM) in both NG 108-15 and rat brain membranes. However, putative mu receptor-selective ligands such as morphine, [D-Ala2, MePhe4, Gly5-ol]enkephalin, [MePhe3, D-Pro4]morphiceptin, and naloxone were less effective inhibitors of [3H][D-Pen2, D-Pen5]enkephalin binding in both systems tested. These data suggest that [3H][D-Pen2, D-Pen5]enkephalin is a potent and selective ligand for the delta opioid receptor.
Akiyama
K
K
Gee
K W
KW
Mosberg
H I
HI
Hruby
V J
VJ
Yamamura
H I
HI
D000818:Animals; D001921:Brain / Q000378:metabolism*; D020881:Enkephalin, D-Penicillamine (2,5)-; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D004745:Enkephalins / Q000378:metabolism*; D005910:Glioma / Q000378:metabolism; D006822:Hybrid Cells / Q000378:metabolism; D007700:Kinetics; D008566:Membranes / Q000378:metabolism; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta
D004745:Enkephalins; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; D020881:Enkephalin, D-Penicillamine (2,5)-