Adrenal medullary opioid receptors are linked to GTP-binding proteins, pertussis toxin substrates.
Effects of Gpp(NH)p and pretreatment of membranes with pertussis toxin (PT) were studied on opioid binding to bovine adrenal medullary opioid receptors. Gpp(NH)p inhibited [3H]DADLE binding by increasing the dissociation constant. PT treatment reduced [3H]DADLE binding and almost abolished the Gpp(NH)p inhibition of [3H]DADLE binding. Levorphanol did not show any significant effect on bovine adrenal medullary adenylate cyclase activity. These results suggest that bovine adrenal medullary opioid receptors are linked to PT-sensitive GTP-binding proteins which are not directly coupled to adenylate cyclase.
Kamikubo
K
K
Department of Internal Medicine (III), Gifu University School of Medicine, Japan.
Murase
H
H
Niwa
M
M
Miura
K
K
Nozaki
M
M
Tsurumi
K
K
D037361:Adenylate Cyclase Toxin; D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives* / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology*; D037342:Pertussis Toxin; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D037361:Adenylate Cyclase Toxin; D011957:Receptors, Opioid; D010566:Virulence Factors, Bordetella; D006165:Guanylyl Imidodiphosphate; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins