Chunk #37 — 4. Selectively bred high alcohol-consuming rat lines and their phenotypic characteristics — 4.5. University of Chile B and University of Chile A rats
The alcohol-preferring [University of Chile B (UChB)] and alcohol-nonpreferring [University of Chile A (UChA)] lines of rats were developed from a Wistar foundation stock at the University of Chile, Santiago, Chile (Mardones and Segovia-Riquelme, 1983). Regarding criteria for an animal model of alcoholism, UChB rats drink 5 g/kg/day or more of ethanol and achieve BACs observed in humans (c.f., Quintanilla et al., 2006, 2008). In addition, UChB rats display relapse-like behavior as indicated by an ADE upon re-exposure to ethanol access (Tampier and Quintanilla, 2011). On the other hand, UChA rats drink approximately 1 g/kg or less ethanol per day (Mardones and Segovia-Riquelme, 1983) which depends, as reviewed by Quintanilla et al. (2006), upon the aldehyde-dehydrogenase-2 (Aldh2, mitochondrial) alleles seen in the respective rat line. These authors indicate that low alcohol-consuming UChA rats have the Aldh22 allele that encodes an enzyme with low affinity for nicotinamide-adenine-dinucleotide (NAD+). On the other hand, the high alcohol-consuming UChB rats either have the Aldh21 or the Aldh23 alleles which have four- to five-fold higher affinities for NAD+. Moreover, the enzyme encoded by Aldh21 has a 33% higher Vmax than those encoded by Aldh22 or Aldh23 (Quintanilla et al., 2006).
