Lactase phlorizin hydrolase synthesis is decreased in protein-malnourished pigs

J Nutr. 1997 May;127(5):687-93. doi: 10.1093/jn/127.5.687.


We have examined the effect of protein malnutrition on brush border (BB) lactase phlorizin hydrolase (LPH) synthesis in young pigs. Two groups of four 3-wk-old pigs were fed diets containing either 19 g soy protein, 63 g carbohydrate and 5 g fat per 100 g diet (a protein-sufficient diet) or 3 g soy protein, 85 g carbohydrate and 5 g fat per 100 g diet (a protein-deficient diet). After 8 wk of consuming the diets, pigs were infused intravenously with 2H3-leucine for 8 h, then killed. The jejunum was collected for measurement of lactase activity, LPH mRNA abundance and the rate of LPH post-translational synthesis. Lactase activities did not differ between groups (mean 8.1 +/- 1.2 micromol x min(-1) x g mucosa(-1)). LPH mRNA abundance relative to elongation factor-1alpha mRNA (the constitutive/reference mRNA) was significantly (P < 0.05) higher in well-nourished pigs (0.36 +/- 0.03%) than in protein-malnourished pigs (0.21 +/- 0.02%). The rate constants of BB LPH post-translational synthesis were also significantly higher in the well-nourished (103 +/- 9% x d(-1)) than in the protein-malnourished pigs (66 +/- 8% x d(-1)). Further, the absolute synthesis rate of BB LPH, a measure of the amount of enzyme synthesized per gram of tissue, was significantly higher in well-nourished than in protein-malnourished pigs (in arbitrary units, 892 +/- 90 vs. 450 +/- 34, respectively). Thus, protein malnutrition affects both LPH mRNA abundance and post-translational processing in young pigs.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Blotting, Northern / methods
  • Diet, Protein-Restricted
  • Jejunum / chemistry
  • Jejunum / cytology
  • Jejunum / enzymology*
  • Lactase-Phlorizin Hydrolase / biosynthesis*
  • Lactase-Phlorizin Hydrolase / genetics
  • Microvilli / chemistry
  • Microvilli / enzymology
  • Protein Biosynthesis / physiology
  • Protein Processing, Post-Translational
  • Protein-Energy Malnutrition / enzymology*
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Serum Albumin / metabolism
  • Swine


  • RNA, Messenger
  • Serum Albumin
  • Lactase-Phlorizin Hydrolase