The influence of methylxanthines on precursor incorporation into protein and RNA of mouse brain.

Pentoxifyline at 1 mM had no effect on [14C]isoleucine incorporation into mouse brain tissue suspension. At 5-20 mM, this compound inhibited incorporation. The inhibition was prompt, and it was reversible. Aminophyline at 3-12 mM produced inhibition, but theophyline at 2-16 mM had no effect. Pentoxifylline inhibited the incorporation of uridine into brain RNA to the same extent and with a similar time course as its effect on protein synthesis.