Physiol. Res. 49: 725-728, 2000


Inhibitory Effect of FK 506 and Cyclosporin A on Nitric Oxide Production by LPS-Treated Cultured Rat Macrophages


1Institute of Pharmacology, 2Institute of Biology and 3Department of Ophthalmology, First Faculty of Medicine, Charles University, Prague, Czech Republic

Received January 7, 2000
Accepted June 28, 2000

We analyzed the effect of FK 506 on the production of nitric oxide by macrophages. Isolated rat peritoneal macrophages were cultured for 24 h with or without lipopolysaccharide (LPS) (5 µg/ml) and in the absence or presence of FK 506 (0.1 and 1 µg/ml). The concentration of NO2- in culture supernatants was taken as a measure of nitric oxide production. FK 506 (0.1 and 1 µg/ml) reduced the LPS-induced increase of NO2- levels by 68 % and 81 %, respectively. The impact of cyclosporin A (CsA) was studied in order to compare their effects. CsA (0.1 and 1 µg/ml) decreased the levels of nitrites by 39 % and 69 %, respectively. The results obtained suggest that both immunosuppressive drugs exhibit a dose-dependent inhibitory effect on nitric oxide production and that FK 506 is a more potent agent than CsA in this respect.

Key words
Nitric oxide · NO inhibitor · Activated macrophages · FK 506 · Cyclosporin A

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Dr. Petra Střeštíková, Institute of Pharmacology, First Faculty of Medicine, Albertov 4, 128 00 Prague 2, Czech Republic. E-mail:

© 2000 by the Institute of Physiology, Czech Academy of Sciences