[Aging of the pancreas. Its implication in malnutrition states in elderly persons]. / Vieillissement du pancréas. Son implication dans les états de dénutrition chez les personnes âgées.

The influence of ageing on exocrine pancreatic function was investigated in rats and in men. Young rats (3-months old, 150-200 g) and old rats (24-month old, 400-500 g) were killed after fasting overnight. Small pancreatic fragments were removed and kept for stereological analysis both in light and electron microscopy; in addition, levels of tritium-labelled leucine uptake and protein synthesis were measured by quantitative histoautoradiography on isolated acini in vitro. The human study was conducted retrospectively in 27 adults (mean age 36 +/- 1.5 years) and in 28 elderly subjects (mean age 72 +/- 0.6 years) with no clinical or radiological evidence of pancreatitis. Duodenal aspirates were taken over a 90 min period under secretin (0.5 U/kg.h) and cerulein (75 U/kg.h) infusion for comparisons of bicarbonate, lipase, chymotrypsin and amylase concentrations and outputs in the two groups. Elderly people were found to have significant and parallel decreases in bicarbonate, lipase and amylase output as compared to younger subjects (-40 per cent, P less than 0.001). The pancreatic deficiency was confirmed in rats by a significant decrease in zymogen volume density and zymogen diameter and a defect of protein synthesis with significant slowing down (-70 per cent, P less than 0.001) of newly synthesized protein transfer to the Golgian zone of acinar cells. Signs of exocrine parenchyma dystrophy (pancreatitis?) were also observed.