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ALTERATIONS IN BRAIN RNA METABOLISM FOLLOWING CHRONIC ETHANOL INGESTION
Author(s) -
Tewari S.,
Fleming E. W.,
Noble E. P.
Publication year - 1975
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1975.tb07675.x
Subject(s) - rna , ingestion , ethanol , orotic acid , biochemistry , in vivo , metabolism , ribosomal rna , cytoplasm , nucleus , biology , chemistry , nucleotide , microbiology and biotechnology , gene
— The in vivo labelling of various brain RNA fractions was found to be altered due to chronic ethanol ingestion by C57BL/6J mice. Ingestion of ethanol resulted in a marked decrease in the incorporation of intraventricularly injected [5‐ 3 H] orotic acid into tRNA, rRNA and polyribosomal RNA. The inhibition was more pronounced in the polyribosomal fraction than the ribosomal fraction. In the nucleus, a biphasic effect of ethanol was demonstrated in the nRNA fraction where increased incorporation of precursor label at early time points was followed by marked depression. Absence of a similar increase in the cytoplasmic RNA fractions is suggestive of a possible defect in the transport of RNA from nucleus to cytoplasm resulting in the accumulation of RNA in the nucleus. Ethanol ingestion had no effect on the synthesis of acid soluble nucleotides following the in vivo administration of [5‐ 3 H]orotic acid or [5‐ 3 H]uridine into the brain. Over 90 per cent of the radioactivity in either ‘control’ or ‘ethanol’ brain could be recovered in the UMP fraction with negligible conversion to GMP, AMP or CMP. The results suggest that the observed changes in RNA metabolism following chronic ethanol ingestion are due to an alteration in the transcription and/or the processing of RNA in the nucleus rather than a function of reduced availability of nucleotides.