AJP - Gastrointestinal and Liver Physiology, Vol 248, Issue 6 626-G632, Copyright © 1985 by American Physiological Society
Sequential disaccharidase loss in rat intestinal blind loops: impact of malnutrition
P. Sherman, A. Wesley and G. Forstner
We studied lactase, maltase, and sucrase activities in the mucosa of
self-filling blind loops (SFBL) in adult rats at weekly intervals after
SFBL formation in order to determine the sequence in which disaccharidase
activities fall. The studies were carried out on nourished and malnourished
rats and extended to a recovery period induced by antibiotics to determine
the effects of malnutrition on the establishment and repair of
disaccharidase deficiencies caused by bacterial overgrowth. Malnutrition
was produced by feeding 50% of the intake of paired rats fed ad libitum.
Disaccharidase activities were determined in SFBL from nourished and
malnourished rats at 7-day intervals until pandisaccharidase deficiency was
established and during a 2-wk recovery period induced by antibiotics.
Maximal SFBL bacterial counts in both nourished and malnourished groups of
rats and brush-border glycoprotein degradation ratios were established at 7
days. In nourished rats only lactase was deficient at 7 days; maltase and
sucrase fell later and sequentially. In malnourished rats all three
disaccharidases were reduced at 7 days. Disaccharidase activities in
self-emptying blind loops (SEBL), used as operated controls, were not
decreased 28 days after surgery. Malnutrition had no effect on
disaccharidase activities in the SEBL, and malnutrition did not affect
recovery rates with antibiotic therapy. We conclude that small intestinal
bacterial overgrowth causes a staggered loss of disaccharidase activities
beginning with the loss of lactase activity. In the presence of bacterial
overgrowth, malnutrition accelerates the conversion of a mono- to a
pan-disaccharidase deficiency.
