Transcriptional regulation of an aldolase gene in the regenerating rat liver.

The relative abundance of rat aldolase A, B, C, alpha-fetoprotein, and albumin mRNAs was determined by Northern hybridization during liver regeneration after partial hepatectomy. Aldolase A mRNA increased more than 10-fold on the 3rd day after partial resection compared with that of normal adult rat liver. S1 analysis revealed that three species of aldolase A mRNAs (mRNA I, II & III) reappeared. However, transcriptional rate of aldolase A mRNA did not change at all during the regeneration. In contrast, aldolase B, aldolase C and albumin mRNAs did not change at all. These findings suggest that the differentiated hepatocyte maintains a differentiated state during the liver regeneration as seen in aldolase B, whereas "oncofetal" isozymes such as aldolase A resurge after partial hepatectomy under the control of post-transcriptional mechanism.