Effect of high retinoid doses on RAR-beta mRNA expression in female B6D2F1 mice.
ABSTRACT The expression of retinoid receptors is altered during the development of several types of cancer. In the present study, we determined the influence of high dietary concentrations of 4-hydroxyphenylretinamide (4-HPR) and 13-cis-retinoic acid (13-cis-RA) on RAR-beta mRNA expression in female mice. Expression of liver and lung RAR-beta RNA increased with increasing levels of dietary retinoid (both 4-HPR and 13-cis RA). Bladder RAR-beta mRNA levels, however, were significantly decreased in mice fed 13-cis RA or 4-HPR. These results suggest that feeding high levels of retinoids to mice results in tissue-specific elfects on expression of RAR-beta mRNA.