Vitamin A regulates the expression of apolipoprotein AI and CIII genes in the rat.

The effect of vitamin A on the expression of apoAI and CIII genes in intact rats was studied. In vitamin A-deficient rats, the hepatic level of apoAI mRNA was increased and enhanced by an oral administration of excess retinoic acid(RA). A similar administration to normal rats caused an increase in the apoAI mRNA level in the intestine without affecting that of hepatic mRNA. Though the hepatic level of apo CIII mRNA was not affected by the vitamin A status, the intestinal level was positively regulated by vitamin A. These findings show that vitamin A regulates the expression of apolipoprotein AI and CIII genes in a tissue-specific and complex fashion.