engleski

The influence of age on intestinal dipeptidyl peptidase IV (DPP IV/CD26), disaccharidases and alkaline phosphatase enzyme activity in C57Bl/6 mice

Introduction: The process of digestion takes place in the intestinal lumen, mediated by a large number of hydrolases secreted in the gastrointestinal tract or produced by the enterocytes in the brush border. Loss of intestinal brush border membrane (BBM) enzymes in aged animals could result in impaired digestion and absorption of all nutrients, which could consequently lead to malnutrition in older age. Objective: The objective of this study was to determine and describe the age-related changes in intestinal BBM enzyme activities which occur in C57Bl/6 mice. Methods: Wild type C57Bl/6 male mice aged 2-weeks, 1-, 2-, 3-, 6- and 12-months were used in this study. Three intestinal segments were analyzed: jejunum, duodenum and ileum. The relationship between ageing and BBM enzymes was characterized using a multiple-sampling technique that quantifies intestinal enzyme activity. Specific dipeptidyl peptidase IV/CD26, disaccharidases (lactase, sucrase and maltase) and alkaline phosphatase activities were determined spectrophotometrically. Results: An emphasized correlation between analyzed BBM enzyme activities and animal age was found. Our study revealed that total intestinal dipeptidyl peptidase IV/CD26, lactase, sucrase, maltase and alkaline phosphatase activities decline significantly with age (P<0, 05). Nevertheless, the horizontal enzyme activity patterns are not affected by age. All the analyzed enzymes showed a similar patter of distribution among the intestine: the highest values were always detected in the jejunum, except for alkaline phosphatase, which highest activity was noticed in the duodenum. Conclusion: Age is an important factor which influences the intestinal BBM enzyme activity. The age-related decline in enzyme activity, if extrapolated to humans, may have important implications for the digestion in the elderly.

Ageing; C57BL/6 mice; Dipeptidyl peptidase IV (DPP IV/CD26); Disaccharidases; Alkaline phosphatase

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