BACKGROUND: The aim of this study was to quantitatively evaluate the relative contributions to in vivo lipolysis of gastric and pancreatic lipases. METHODS: Gastric and pancreatic lipase secretions were measured, and their respective levels were determined in duodenal fluid during the digestion of a liquid test meal in healthy volunteers. Gastric lipase activity was clearly distinguished from that of pancreatic lipase by using both a specific enzymatic assay and an enzyme-linked immunosorbent assay. Lipolysis products were monitored throughout the digestion period. RESULTS: On a weight basis, the ratio of pancreatic lipase to gastric lipase total secretory outputs was found to be around four after 3 hours of digestion. The level of gastric hydrolysis was calculated to be 10% +/- 1% of the acyl chains released from the meal triglycerides. Gastric lipase remained active in the duodenum where it might still hydrolyze 7.5% of the triglyceride acyl chains. CONCLUSIONS: Globally during the whole digestion period, gastric lipase might hydrolyze 17.5% of the triglyceride acyl chains. In other words, gastric lipase might hydrolyze 1 acyl chain of 4, which need to be hydrolyzed for a complete intestinal absorption of monoglycerides and free fatty acids resulting from the degradation of two triglyceride molecules.
BACKGROUND: The aim of this study was to quantitatively evaluate the relative contributions to in vivo lipolysis of gastric and pancreatic lipases. METHODS: Gastric and pancreatic lipase secretions were measured, and their respective levels were determined in duodenal fluid during the digestion of a liquid test meal in healthy volunteers. Gastric lipase activity was clearly distinguished from that of pancreatic lipase by using both a specific enzymatic assay and an enzyme-linked immunosorbent assay. Lipolysis products were monitored throughout the digestion period. RESULTS: On a weight basis, the ratio of pancreatic lipase to gastric lipase total secretory outputs was found to be around four after 3 hours of digestion. The level of gastric hydrolysis was calculated to be 10% +/- 1% of the acyl chains released from the meal triglycerides. Gastric lipase remained active in the duodenum where it might still hydrolyze 7.5% of the triglyceride acyl chains. CONCLUSIONS: Globally during the whole digestion period, gastric lipase might hydrolyze 17.5% of the triglyceride acyl chains. In other words, gastric lipase might hydrolyze 1 acyl chain of 4, which need to be hydrolyzed for a complete intestinal absorption of monoglycerides and free fatty acids resulting from the degradation of two triglyceride molecules.
Authors: Harry P F Peters; Elisabeth C M Bouwens; Ewoud A H Schuring; Edward Haddeman; Krassimir P Velikov; Sergey M Melnikov Journal: Eur J Nutr Date: 2013-08-23 Impact factor: 5.614