Inhibitory effect of cyclosporin A and FK506 on nitric oxide production by cultured macrophages. Evidence of a direct effect on nitric oxide synthase activity.
Casein-elicited peritoneal macrophages from mice were cultured either alone or with interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS), and the effect of cyclosporin A (CsA) and FK506 on NO2- production (due technical difficulties NO2- was taken as the index for NO) was analysed. We observed an inhibitory effect of CsA and FK506 on NO2- production. The IC50 for NO2- production by casein-elicited macrophages was 0.1 microgram/ml for CsA and 0.3 microgram/ml FK506. The effect of both drugs was dose-dependent and was more clear in non-stimulated macrophages. The presence of IFN-gamma and LPS in the culture increased NO2- production by casein-elicited macrophages and partially eliminated the inhibition exerted by CsA and FK506. Both drugs acted directly on the nitric oxide synthase (NOS), since CsA and FK506 reduced by 35% and by 17%, respectively, NOS activity in the crude cytosolic fraction. However, CsA and FK506 did not alter 14CO2 production from [1-14C]glucose, suggesting that the pentose monophosphate pathway activity was not modified. These data add new insight into the interpretation of the immunosuppressive properties of both drugs.
Conde
M
M
Departmento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain.
Andrade
J
J
Bedoya
F J
FJ
Santa Maria
C
C
Sobrino
F
F
D000594:Amino Acid Oxidoreductases / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D007773:Lactates / Q000096:biosynthesis; D019344:Lactic Acid; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D010427:Pentose Phosphate Pathway / Q000187:drug effects; D016559:Tacrolimus / Q000494:pharmacology*
D007773:Lactates; D009569:Nitric Oxide; D019344:Lactic Acid; D016572:Cyclosporine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D016559:Tacrolimus