Stability of polyribosomes isolated from rat liver after phenobarbital administration.

The effect of daily injections of phenobarbital (75 mg/kg) on the degradation of rat liver polyribosome suspensions during storage in vitro at 0-4° was examined. Sucrose gradient analysis of polysomes isolated from animals treated for 3-5 days with 0.9% NaCl revealed that after 24-48 hr of storage at 0-4° a disaggregation of large polysome species occurred, together with an increase of 50-85% in the number of monomer and dimer species. In contrast, polyribosomes derived from rats treated with phenobarbital for 3-5 days were shown to be almost completely resistant to degradation under the same conditions.