Serum pseudocholinesterase and very-low-density lipoprotein metabolism.

Serum pseudocholinesterase (PChE) was discovered in 1932. Since this protein mimics many of the catalytic properties of acetylcholinesterase, it has traditionally been referred to as PChE, even though its true biological function is unknown. Serum PChE is synthesized in the liver and secreted into the circulation as a sialated glycoprotein. Although no convincing evidence of biological function exists, a significant number of obese and diabetic patients have elevated levels of PChE. The same phenomenon is found in experimental animal models of obesity, diabetes and hyperlipoproteinemia. Streptozotocin-induced diabetic mice showed increased serum PChE activity concomitant with increased serum triacylglycerol and PChE activity declined with treatment. Iso-OMPA, a nontoxic inhibitor of serum PChE, reduced serum and liver triacylglycerols and serum VLDL in streptozotocin-induced rodent diabetes. These findings suggest that PChE may have a role in VLDL metabolism.