INTESTINAL RESECTION AND URSODEOXYCHOLIC ACID - EFFECT ON HEPATIC 3-HYDROXY-3-METHYLGLUTARYL COENZYME-A REDUCTASE AND ACYL-COA-CHOLESTEROL ACYLTRANSFERASE ACTIVITIES IN THE RAT

The effect of distal small bowel resection (DSBR) and/or ursodeoxychol ic acid (UDCA) ingestion on hepatic activities of 3-hydroxy-3-methylgl utaryl Coenzyme A (HMG-CoA) reductase and acyl-CoA:cholesterol acyltra nsferase (ACAT) was studied in rats. The total activity and the activi ty state of the enzyme HMG-CoA reductase were also determined. DSBR si gnificantly increased the total activity of HMG-CoA reductase. This in crease was enhanced when rats were treated with UDCA. The active form of the enzyme was increased by DSBR. However, the ingestion of UDCA di d not modify these results. Therefore, the observed increase in the to tal activity of HMG-CoA reductase in resected-rats after the administr ation of UDCA was due to an increase in the inactive form of the enzym e. The activity of ACAT was decreased in resected animals. This decrea se was greater after the treatment of UDCA in resected rats when compa red with the corresponding group of untreated rats with UDCA. We concl ude that UDCA ingestion increases the effect of intestinal resection o n hepatic HMG-CoA reductase and ACAT activities.