AJP - Gastrointestinal and Liver Physiology, Vol 238, Issue 2 114-G118, Copyright © 1980 by American Physiological Society
Effect of genetic diabetes on enzymes of mouse intestinal brush-border membrane
K. Ramaswamy and P. W. Flint
Activities of intestinal enzymes were measured in genetically diabetic
mouse of strain C57BL/KsJ-dbm to determine the long-term effects of genetic
and uncontrolled diabetes on intestinal digestive function. Specific
activities of enzymes were measured in intestinal homogenates, brush-border
membrane fractions, and everted sacs from diabetic mice and their
littermate controls. Sucrase, maltase, trehalase, alkaline phosphatase, and
leucylnaphthylamidase activities were elevated in diabetes; lactase did not
show any changes. The increases in disaccharidase activities in diabetes
were in homogenates from both proximal and distal intestine but the
increases in distal were more pronounced than in the proximal. Measurement
of enzyme activities in brush-border membrane fractions showed a pattern
similar to that observed in homogenates. Hydrolysis of sucrose and
trehalose by everted sacs was markedly higher in the diabetic mice. It is
therefore concluded that in genetic diabetes the digestive function of the
intestine is stimulated, that the increased enzymes were incorporated into
the brush-border membrane, and that the additional enzymes are accessible
to the substrates in the intestinal lumen and so of physiological
significance.
