Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied possible coupling of opioid receptors to GTP-binding proteins to clarify the mechanism(s) of opioid action in bovine adrenal medullary membranes. Guanylyl imidodiphosphate (Gpp(NH)p) reduced the binding of [3H] D-Ala2-D-Leu5-enkephalin ([3H] DADLE) to bovine adrenal medullary membranes dose-dependently, and enhanced the binding of [3H] diprenorphine to them. Gpp(NH)p (0.1 mM) enhanced the Kd value of the [3H] DADLE binding from 2.9 nM to 3.9 nM, but did not change its Bmax. Pretreatment of bovine adrenal medullary membranes with pertussis toxin (PT) reduced the [3H] DADLE binding. The Gpp(NH)p inhibition for [3H] DADLE binding was diminished by the PT-pretreatment. On the other hand, the [3H] diprenorphine binding to PT-pretreated membranes was higher than that to control membranes. Levorphanol inhibited the adenylate cyclase activity of the rat caudate nucleus crude synaptosomal fraction, but did not change that of bovine adrenal medullary membranes. These results suggest that opioid receptors in bovine adrenal medullary membranes are coupled to PT-sensitive GTP-binding protein which may not influence on adenylate cyclase.
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PMID:[Characterization of adrenal medullary opioid receptors. II. Coupling of adrenal medullary opioid receptors to GTP binding proteins]. 282

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.
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PMID:Adrenal medullary opioid receptors are linked to GTP-binding proteins, pertussis toxin substrates. 282 56