Insulin-induced expression of prostacyclin receptors on platelets is mediated through ADP-ribosylation of Gi alpha protein.
The binding of insulin in physiological amounts to human blood platelets, which increases adenylate cyclase-linked prostacyclin receptor numbers on the cell surface, was found to be directly related to the ADP-ribosylation of the Gi alpha. Conversely, resuspension of the insulin-treated platelets in the hormone-free medium decreased both the prostaglandin receptor numbers and ADP-ribosylation of Gi alpha. Furthermore, incubation of platelets with pertussis toxin or its A-protomer, which ADP-ribosylates Gi alpha, also stimulated the binding of the prostanoid. These results suggest that the increase of prostacyclin receptor numbers in platelets is mediated through the ADP-ribosylation of Gi alpha.
Kahn
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Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D037361:Adenylate Cyclase Toxin; D000527:Alprostadil / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology / Q000502:physiology*; D007457:Iodine Radioisotopes; D037342:Pertussis Toxin; D044006:Receptors, Epoprostenol; D011982:Receptors, Prostaglandin / Q000096:biosynthesis*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D007004:Hypoglycemic Agents; D007328:Insulin; D007457:Iodine Radioisotopes; D044006:Receptors, Epoprostenol; D011982:Receptors, Prostaglandin; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D002772:Cholera Toxin; D000242:Cyclic AMP; D037342:Pertussis Toxin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D000527:Alprostadil