Pancreatic lipase and colipase activity increase in pancreatic acinar tissue of diabetic rats.
We studied the lipase and colipase activity in pancreatic acinar tissue of insulin-deficiency and insulin-resistance obese Zucker rats (fa/fa). After injection of streptozotocin (STX 75 mg/kg) in normal Sprague-Dawley rats, the activity of lipase and colipase in pancreatic acinar tissue was increased by approximately 100%, the increase in colipase occurring 3 days later than that of lipase. At the same time, the amylase activity was decreased by 98%. Injection of alloxan (125 mg/kg) induced a similar change of pancreatic enzyme pattern, with amylase activity strongly reduced by 79% and activity of lipase and colipase increased 20.5 and 18.6%, respectively. Correction of the diabetic state with insulin (1 U/100 g/day) reversed the activity of these enzymes to their prediabetic levels. Administration of insulin (6 U/100 g/day) to normal Sprague-Dawley rats increased the activity of amylase as well as lipase and colipase, whereas injection of glucagon (0.3 mg/100 g/day) decreased the activity of amylase and colipase but had no significant effect on lipase activity. In the obese Zucker rats (fa/fa), the activity of lipase and colipase at onset of obesity (5 weeks of age) was lower than that in their lean littermates (fa/o). Thereafter the activity of the two proteins increased with age, being 40% higher in the fa/fa rat than in the fa/o rat at age 7 weeks. During the same period, amylase activity decreased. These results indicate that pancreatic lipase and colipase activity are increased following either insulin deficiency or insulin resistance in rats by a mechanism related to the changed levels of insulin.
Duan
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RD
Department of Physiological Chemistry, University of Lund, Sweden.
Erlanson-Albertsson
C
C
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003089:Colipases / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005260:Female; D005934:Glucagon / Q000097:blood / Q000494:pharmacology; D007328:Insulin / Q000097:blood; D008049:Lipase / Q000378:metabolism*; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011924:Rats, Zucker; D012016:Reference Values; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D003089:Colipases; D007328:Insulin; D011506:Proteins; D014280:Triglycerides; D005934:Glucagon; D008049:Lipase; D000681:Amylases