Lipid composition and 3-hydroxy-3-methylglutaryl-CoA reductase activity of acinar cell carcinoma of rat pancreas.
The lipid composition and 3-hydroxy-3-methylglutaryl-CoA reductase activity of subcutaneous transplantable pancreatic acinar cell tumors on nude mice were compared with those of normal, regenerating, fetal and newborn rat pancreata. The tumors and also the fetal tissues showed decreased concentration in total lipids, increased concentration in sphingomyelin and an increase in cholesterol when compared to normal rat pancreas. The regenerating pancreas showed an intermediate elevation in these lipid parameters. Specifically, only tumor showed an increase in phosphatidylethanolamine/phosphatidylcholine ratio. The tumors and also the fetal tissues showed an increase in hydroxymethylglutaryl-CoA reductase activities, suggesting that the de novo synthesis of cholesterol is a requirement for cell proliferation. The cholesterol metabolism in normal tissues is under metabolic regulation as indicated by decreased hydroxymethylglutaryl-CoA reductase activities and decreased cholesterol concentration in postnatal tissues when compared with the fetal tissues. The fast growing AT3A tumor showed higher hydroxymethylglutaryl-CoA reductase activity when compared to the slow growing AT3B tumor, indicating that the differences in growth rate of the tumors may be related at least in part to differences in their cholesterol metabolism.
D000818:Animals; D005260:Female; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism*; D008055:Lipids / Q000032:analysis*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010179:Pancreas / Q000502:physiology; D010190:Pancreatic Neoplasms / Q000032:analysis* / Q000201:enzymology; D010743:Phospholipids / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012038:Regeneration
D008055:Lipids; D010743:Phospholipids; D006903:Hydroxymethylglutaryl CoA Reductases