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Biomedical subjects

M P Lamden

Publications and source records attributed to M P Lamden.

2 recordsLinked to original sources

Inability of vitamin A deficiency to alter benzo(a)pyrene metabolism in Syrian hamsters.

Syrian golden hamsters were placed on a control or vitamin A-deficient diet. When their serum vitamin A content was significantly reduced, i.e., to less than 10% of controls, the hamsters were killed and lung aryl hydrocarbon hydroxylase activity and metabolism of benzo(a)pyrene were determined. The benzo(a)pyrene metabolite profile was similar with control and A-deficient systems, and only few quantitative differences were noted. Addition of beta-retinyl acetate to the in vitro incubations did not substantially affect benzo(a)pyrene metabolism.

Animals

Sensitive fluorometric method for tissue tocopherol analysis.

A sensitive, highly reproducible method for tissue tocopherol analysis that combines saponification in the presence of large nmount of ascorbic acid to remove interfering substances, extraction fo the nonsponifiable lipids with hexane, and fluorometric measurement of the tocopherol is presented. The nonsaponifiable lipids phase contained only one fluorochrome in the 290 am excitation and 330 nm emission range, and it was identified as tocopherol by thin layer and column chromatography. Column chromatography of the hexane extract of a saponified, 14C-tocopherolspiked microsomal fraction showed that no measurable oxidation to tocopherylquinone had occurred. The flurometric method for tocopherol analysis was applied to homogenates and subcellular fractions from rat liver, kidney, lung, and heart and red blood cells. The heavy mitochondrial and microsomal fractions had the highest subcellular concentrations of tocopherol.

Animals