SYNTHESIS OF LIVER CYTOCHROME-P-450B IN A CELL-FREE PROTEIN SYNTHESIZING SYSTEM

Live ppolysomes isolated from rats that had been treated with phenobarbital (PB) are able to incorporate [3H]leucine into total protein in vitro at a rate almost five times that of polysomes prepared from control animals. Specific immunoprecipitation of translational products has shown that polysomes from induced animals synthesize cytochrome P-450b at a rate almost seven times greater than polysomes from control animals. The increased protein and cytochrome P-450b synthesis can be detected as early as 6 h following phenobarbital administration and reaches a maximum at 12-18 h. The results suggest that PB administration effects an increase in mRNA for cytochrome P-450b. © 1979.