REGULATION OF STEROL CARRIER PROTEIN-2 GENE-EXPRESSION IN RAT-LIVER AND SMALL-INTESTINE

Sterol carrier protein-2 (SCP2) is a peroxisomal protein most highly e xpressed in non-steroidogenic tissues such as liver and small intestin e. We have examined SCP2 gene expression during development and after alterations in lipid and bile acid metabolism and compensatory cell gr owth in the rat. The developmental expression Of SCP2 displayed a biph asic pattern of relative mRNA abundance with a peak at day 19 to 20 of fetal life, reaching adult levels by day 14 and after day 14 in small intestine. In adult rats there was no effect on SCP2 mRNA abundance, or the relative proportions of the four SCP2 transcripts after gemfibr ozil treatment, 30-fold changes in hepatic cholesteryl ester and trigl yceride levels, bile ligation, compensatory hepatic or renal growth. H owever, immunoblot analysis of tissue homogenates revealed that SCP2 p rotein is decreased by 75% in the livers of gemfibrozil-treated animal s and increased by 5-fold at 48 h in regenerating liver and in the rem aining kidney after unilateral nephrectomy. Taken together these resul ts suggest that SCP2 gene expression is developmentally regulated and modulated translationally or post-translationally in the adult rat by gemfibrozil and compensatory cell growth.