Rg. Oretti et al., TRYPTOPHAN-PYRROLASE GENE-EXPRESSION IN AN ALCOHOL-PREFERRING AND NONPREFERRING MOUSE STRAIN, Addiction biology, 3(1), 1998, pp. 71-77
There is considerable evidence that the level of cerebral serotonin pl
ays a key role in the volitional consumption of ethanol in both man an
d animals. Naive alcohol-preferring C57BL/6J mice have been shown to h
ave a lower cerebral serotonin content compared to the non-preferring
CBA/Ca mouse strain. This has been attributed to the enhancement of he
patic tryptophan pyrrolase activity in C57 mice. Activity and/or expre
ssion of tryptophan pyrrolase may be an important biological determina
nt of alcohol preference. We have investigated the possible mechanism/
s underlying this strain difference in tryptophan pyrrolase activity b
y assaying both mRNA levels encoding for the tryptophan pyrrolase gene
and by mutational analysis of tryptophan pyrrolase cDNA. We were unab
le to demonstrate any difference in tryptophan pyrrolase mRNA levels b
etween naive C57 and CBA mice. Tryptophan pyrrolase mRNA levels were i
ncreased following starvation in C57 mice and following glucocorticoid
administration in both C57 and CBA mice. Heteroduplex mutational anal
ysis failed to detect any tryptophan pyrrolase cDNA sequence heterogen
eity between these mice strains.