Hepatic level of mRNA in relation to polymorphism and strain difference in expression of cytochrome P-450g.

Hepatic level of mRNA for P-450g was determined in male and female rats of Sprague-Dawley, ACI and Fischer strains using a specific oligonucleotide probe. The mRNA level in female Sprague-Dawley and Fischer rats was undetectable in accordance with a very low or undetectable level of P-450g protein. The mRNA was detected in all male ACI rats, in which high levels of P-450g protein were detected. In Fischer male rats, mRNA for P-450g was clearly detected in the liver, but P-450g protein was not detected. Moreover, the mRNA was detected in the liver of all male Sprague-Dawley rats, irrespective of the expressed level or absence of P-450g protein. As a most plausible explanation of the observed discordance in the levels of P-450g mRNA and protein, translation of unstable protein for microheterogeneous P-450g is discussed.