Effect of cyclosporin A and different vehicles on ATP production in mitochondria isolated from the rat kidney cortex.

Isolated rat kidney mitochondria were exposed in vitro to cyclosporin A and three different vehicles, ethanol, DMSO and cremophor. Spontaneous ATP production and oxidative phosphorylation were measured with a bioluminometric method. Both ethanol and cremophor caused a slight (4-7%) decrease in spontaneous ATP production, and also cyclosporin A itself had a minimal effect. On the other hand DMSO had an opposite effect, causing an increase of about 20%. Cyclosporin A showed a dose dependent inhibition of oxidative phosphorylation, being most pronounced when dissolved in ethanol. Cremophor, the castor oil used in commercial preparations caused per se almost a 40% inhibition of the oxidative phosphorylation.