Extraction and quantification of daunomycin and doxorubicin in tissues.

The measurement of intracellular concentrations of the anti-cancer drug doxorubicin was performed by the application of a simple cell extraction technique combined with a rapid high-performance liquid chromatographic separation. Quantitation was done by fluorescence detection. The extraction procedure was non-degradative and the mean recovery of drug was 95%. A high drug extraction efficiency was confirmed with radiolabeled [3H] doxorubicin. The method is applicable to normal and neoplastic tissue.

The direct spectrophotometric observation of benzo(a)pyrene phenol formation by liver microsomes.

Optical spectral repetitive scan analysis during the oxidative metabolism of benzo(a)pyrene by liver microsomal suspensions reveals the time-dependent formation of an intermediate(s) of which the visible spectra resemble those of several benzo(a)pyrene phenols. Liver microsomes from 3-methylcholanthrene-treated rats showed a greater rate of formation of the phenols than did microsomes from control animals; the rate of formation catalyzed by liver microsomes from phenobarbital-pretreated rats was intermediate. When 3-hydroxybenzo(a)pyrene was used as a standard for comparison of activity, the rates of formation of phenols were compared when measured by fluorometric, spectrophotometric, or high-pressure liquid chromatographic analytical techniques. An epoxide hydrase inhibitor, 1,1,1-trichloropropene-2,3-oxide, enhanced phenol formation regardless of the source of liver microsomes, and 7,8-benzoflavone inhibited control and 3-methylcholanthrene-induced microsomal metabolism of benzo(a)pyrene, 7,8-Benzoflavone did not effect benzo(a)pyrene metabolism by liver microsomes from phenobarbital-pretreated rats. The effect of inhibitors on the spectrophotometric assay correlates well with the results obtained from benzo(a)pyrene metabolite analysis using high-pressure liquid chromatography.