Suckling
Induces Rapid Intestinal Growth and Changes in Brush Border Digestive
Functions of Newborn Pigs
Manuscript received
10 June 1996. Initial reviews completed 30 July 1996. Revision accepted
22 November 1996.
Hongzheng Zhang, Christiane Malo*, and Randal K. Buddington
Department of Biological Sciences, Mississippi State University, Mississippi
State, MS 39762-5759 and * Membrane Transport Research Group, Department
of Physiology, B.P. 6128, Succursale Centre-ville, Universit¨¦ de Montr¨¦al,
Montr¨¦al, Qu¨¦bec, Canada H3C3J7
The interplay between suckling, intestinal growth and brush-border
membrane functions is critical during the perinatal period. The present
study investigates changes in intestinal dimensions, activities of
four brush border membrane hydrolases (lactase, sucrase, maltase and
aminooligopeptidase) and rates of sugar and amino acid uptake by intact
tissues and brush border membrane vesicles during the first 24 h of
suckling. Total intestinal weight, mucosal weight and protein content
increased 58%, 80% and 126% (P < 0.05) during the first 6 h of
suckling; length and surface area did not increase. Total mucosal
DNA content was 4.6-fold higher at 24 h after birth, with the rate
of increase differing among intestinal regions. Hydrolytic capacities
of the entire small intestine increased, more so for homogenates than
for brush border membrane vesicles, and more for lactase relative
to the other hydrolases studied. Rates of nutrient transport declined,
especially for brush border membrane vesicles, for proximal and mid-intestine
relative to distal intestine, and for glucose relative to galactose
and amino acids. We conclude that 1) changes in brush border membrane
digestive functions coincide with rapid intestinal growth, with postnatal
patterns varying among hydrolases, transporters and regions; 2) insertion
into the brush border membrane, not synthesis, limits the postnatal
increase of hydrolase activity; and 3) despite declines in specific
activity, hydrolytic and glucose transport capacities of the entire
intestine remained stable or increased, and exceeded estimated dietary
loads because of intestinal growth.
Key words: colostrum, neonatal, pigs, nutrient transport, brush border
hydrolases.
American Journal
of Clinical Nutrition, Vol 34, 252-257, Copyright ? 1981 by The American
Society for Clinical Nutrition, Inc
Articles
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