Measurement of early events in signal transduction beyond receptors involving G proteins function in mononuclear leucocytes.
G protein function in human mononuclear leucocytes was measured through isoproterenol, carbamylcholine and dopamine-enhanced 3H-Gpp(NH)p binding. Dopamine and carbamylcholine exerted their effects through D5 and M2 receptors, respectively. ADP-ribosylation by bacterial toxins indicates that dopamine and isoproterenol affected Gs, while carbamylcholine affected Gi. Quantitative G proteins measures were conducted through immunoblot analyses with specific polyclonal antibodies against G alpha s, and G alpha i subunits. Simultaneous functional and quantitative measures of G proteins showed significant correlations between function and immunoreactivities. Agonist-enhanced guanine nucleotide exchange is thus suggested as a method for measurement of early events in signal transduction beyond receptors in leucocytes, which can potentially serve for detecting alterations in G proteins measures in human disease.
Avissar
S
S
Department of Clinical Pharmacology, Faculty for Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel. sofia@bgumail.bgu.ac.il
Schreiber
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G
D000262:Adenylyl Cyclases / Q000378:metabolism; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000328:Adult; D000368:Aged; D002217:Carbachol / Q000494:pharmacology; D003866:Depressive Disorder / Q000378:metabolism; D004298:Dopamine / Q000494:pharmacology; D005260:Female; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000187:drug effects; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000187:drug effects; D019204:GTP-Binding Proteins / Q000502:physiology*; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007545:Isoproterenol / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D018721:Muscarinic Agonists / Q000494:pharmacology; D037342:Pertussis Toxin; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000187:drug effects; D011954:Receptors, Dopamine / Q000187:drug effects; D011976:Receptors, Muscarinic / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D018721:Muscarinic Agonists; D011943:Receptors, Adrenergic, beta; D011954:Receptors, Dopamine; D011976:Receptors, Muscarinic; D010566:Virulence Factors, Bordetella; D006165:Guanylyl Imidodiphosphate; D002217:Carbachol; D011065:Poly(ADP-ribose) Polymerases; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019205:GTP-Binding Protein alpha Subunits, Gs; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D004298:Dopamine