title: Different concentrations of pertussis toxin have opposite effects on agonist-induced PGE2 formation in mesangial cells.
abstract: Pertussis toxin may inactivate N proteins linked to phospholipase C. We examined the effect of pretreatment with pertussis toxin at different concentrations and times on agonist-induced PGE2 synthesis in mesangial cells. Two to four hours with 10-50 ng/ml of pertussis toxin inhibited the response to angiotensin and platelet activating factor, but with a different sensitivity. This was associated with decreased [14C]arachidonic acid release in prelabeled cells. The response to A23187 was unaltered. At high concentrations (1 to 5 micrograms/ml) pertussis toxin increased basal PGE2 and the response to all agonists. Pertussis toxin pretreatment resulted in a dose-dependent ribosylation of a 40 kDa protein band. Thus, responses to different agonists have different sensitivity to pertussis toxin inhibition, which at high concentrations may even have opposite effects.
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D015232:Dinoprostone; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000502:physiology*; D066298:In Vitro Techniques; D007678:Kidney Glomerulus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D037342:Pertussis Toxin; D010972:Platelet Activating Factor / Q000494:pharmacology; D011458:Prostaglandins E / Q000096:biosynthesis*; D051381:Rats; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
chemical_list: D008565:Membrane Proteins; D010972:Platelet Activating Factor; D011458:Prostaglandins E; D010566:Virulence Factors, Bordetella; D009243:NAD; D000804:Angiotensin II; D000001:Calcimycin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D015232:Dinoprostone