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Summary. a-amylase activity variations in the parietal and intraluminal contents of the digestive tract in control and pancreatic duct ligated rabbits. a-amylase activity (E.C.3.2.1 .1) was studied in the parietal and intraluminal contents of different parts of the digestive tract in control (T) and pancreatic duct ligated rabbits (P-). Maximal activity at the parietal level in control rabbits was observed in the median part of the duodenum (392 ! 37 fL M/maltose/g/min at 37 °C). Weak activity (3 p. 100 of the duodenal activity) was seen in other parts of the small and large bowel. Variations in a-amylase activity were noted in the post-ligature period in rabbits. This activity declined by 38 p. 100 2 weeks after ligature ; normal values reappeared 6 weeks later, and 10 weeks after the operation the values were 40 p. 100 higher than those of control rabbits. Maximal intraluminal content activity was observed in the jejunum and ileum of T rabbits (182 !26 and 92 ! 6 y m jmaltosejg jmin at 37 °C).The large bowel showed only 5 p. 100 of the jejunal activity. In P-rabbits, a-amylase activity progressively increased only in the large bowel from 2 and 6 weeks ( x 3) to 10 weeks ( x 6). Suppression of pancreatic digestion was followed by a compensative process. Hyperplasia and hypertrophy of Briinner's glands could explain the rise in a-amylase activity at the duodenal level. The elevation observed in intraluminal contents was certainly of bacterial origin.Il est connu que chez des animaux qui présentent des troubles pancréatiques, il apparaît souvent une variation des activités enzymatiques intestinales. Plus précisé-ment, dans le cas de déficience pancréatique exocrine, certains auteurs ont pu constater une élévation des hydrolases glucidiques, principalement des disaccharidases (Cerda, Preiser et Crane, 1972 ;Madzarovova-Nohejlova, 1976

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Kinetic studies of the histochemical and histoenzymatic behavior of rabbit pancreatic parenchymas were performed 5, 30 and 90 days after Wirsung duct ligation. In control pancreas, some enzyme activities (EA) were more prominent in Langerhans islets [glucose-6-phosphatase, glucose-6-phosphate dehydrogenase (DH), isocitrate DH, glycerol-3-phosphate DH, NADPH DH], others were strongly marked in acini and ducts (alkaline phosphatase, beta-glucuronidase, acid esterase aryl-sulfatase). Histochemical and enzyme abnormalities observed in experimental rabbits reflect the post-ligation degenerative and reactive processes in both exocrine and endocrine pancreas: (1) the decrease in Krebs cycle and pentose pathway linked EA and the increased lysosomal and acid phosphatase EA reflect early (day 5) degeneration and necrosis of islets and acini (day 30); (2) proliferative processes in developed ductal epithelia are shown by an increase in both glycolytic and lysosomal EA (days 30 and 90); (3) connective tissue neogenesis and interstitial fibrosis occurred as shown by activated beta-glucuronidase, aryl-sulfatase, alkaline phosphatase and increased ribonucleoproteins and glycoaminoglycans contents (day 30); (4) on day 90, the neoformed cell clusters presenting glucose-6-phosphatase positivity (B-cell marker) are seen in the pancreas remnant. At the same time, blood insulin level increases correlated with a decrease of hyperglycemia.