DISTRIBUTION OF ALCOHOL AND SORBITOL DEHYDROGENASES - ASSESSMENT OF MESSENGER-RNA SPECIES IN MAMMALIAN-TISSUES

The tissue distribution of mRNA of alcohol dehydrogenases of classes I , II and III, and sorbitol dehydrogenase, was studied. mRNA from 19 di fferent rat tissues was purified and analyzed by Northern blots, utili zing cDNA probes specific for the four dehydrogenases. Class-I alcohol -dehydrogenase mRNA was shown to be of widespread occurrence, detectab le in all tissues including brain, but with pronounced differences in amounts. Hybridization revealed the pattern of occurrence of class-II alcohol-dehydrogenase mRNA to be unique, with transcripts only in the liver, duodenum, kidney, stomach, spleen and testis. Abundant levels o f class-III alcohol-dehydrogenase (glutathione-dependent formaldehyde dehydrogenase) mRNA were present in all tissues analyzed, reflecting t he general need for scavenging of formaldehyde in physiological cytopr otection. Sorbitol dehydrogenase mRNA was detected in all tissues exce pt small intestine, in agreement with sorbitol resorbtion by passive d iffusion in this tissue. In addition, evidence for a sex-specific expr ession, in the liver, of class-II alcohol dehydrogenase was obtained.