Summary: | Thesis (M.Sc.)--Memorial University of Newfoundland, 2008. Biochemistry Includes bibliographical references (leaves 73-80) Intestinal mucin synthesis is sensitive to dietary threonine supply which suggests that the gut's requirement for threonine may comprise a significant proportion of the whole body requirement. We used a continuously perfused gut loop model and intraluminal flooding dose technique in six young pigs to study the acute effects of varying luminal availability of threonine on intestinal protein and mucin syntheses. A complete amino acid mixture containing 0, 75 or 200% of the whole body threonine requirement was continuously perfused in isolated loops for 120 min, including a 30 min 3H-phenylalanine flooding dose. Fractional synthesis rates of total mucosal protein and mucin were measured by analyzing 3H-phenylalanine incorporation. Fractional rates of total mucosal protein synthesis were significantly higher in loops perfused with solutions containing threonine at 200% (66 ± 4 %/d) compared to 0% (42 ± 9 %/d) and 75% (53 ± 6 %/d) (P < 0.05). For mucin, fractional rates of synthesis were significantly different between 0% (323 ± 72%/d), 75% (347 ± 49 %/d) and 200% (414 + 31 %/d) (P < 0.05).
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