Loss of exocrine pancreatic stimulation during parenteral feeding suppresses digestive enzyme expression and induces Hsp70 expression

Am J Physiol Gastrointest Liver Physiol. 2007 Mar;292(3):G857-66. doi: 10.1152/ajpgi.00467.2006. Epub 2006 Nov 30.


Luminal nutrients are essential for the growth and maintenance of digestive tissue including the pancreas and small intestinal mucosa. Long-term loss of luminal nutrients such as during animal hibernation has been shown to result in mucosal atrophy and a corresponding stress response characterized by the induction of heat shock protein (Hsp)70 expression. This study was conducted to determine if the loss of luminal nutrients during total parenteral nutrition (TPN) would result in atrophy of the exocrine pancreas and small intestinal mucosa as well as an induction of Hsp70 expression in rats. In experiment 1, the treatment groups included an orally fed control, a saline-infused surgical control, or TPN treatment for 7 days. In experiment 2, the treatment groups included an orally fed control and TPN alone or coinfused with varying doses of glucagon-like peptide (GLP)-2, a mucosal proliferation agent, for 7 days. In experiment 1, TPN resulted in a 40% reduction in pancreatic mass that was associated with a dramatic reduction in digestive enzyme expression, enhanced apoptosis, and a 200% increase in Hsp70 expression. Conversely, heat shock cognate 70, Hsp27, and Hsp60 expression was not changed in the pancreas. In experiment 2, TPN resulted in a 30% reduction in jejunal mucosa mass and a similar induction of Hsp70 expression. The inclusion of GLP-2 during TPN attenuated jejunal mucosal atrophy and inhibited Hsp70 expression, suggesting that Hsp70 induction is sensitive to cell growth. These data indicate that pancreatic and intestinal mucosal atrophy caused by a loss of luminal nutrient stimulation is accompanied by a compensatory response involving Hsp70.

Publication types

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

MeSH terms

  • Amylases / blood
  • Amylases / metabolism
  • Animals
  • Apoptosis / physiology
  • Atrophy / etiology
  • Atrophy / prevention & control
  • Body Weight
  • Chaperonin 60 / metabolism
  • Enzyme Precursors / analysis
  • Enzyme Precursors / metabolism*
  • Glucagon-Like Peptide 2 / pharmacology
  • HSC70 Heat-Shock Proteins / metabolism
  • HSP27 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins / metabolism*
  • Heat-Shock Proteins / metabolism
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology
  • Jejunum / drug effects
  • Jejunum / metabolism
  • Jejunum / pathology
  • Lipase / metabolism
  • Male
  • Neoplasm Proteins / metabolism
  • Organ Size
  • Pancreas / chemistry
  • Pancreas / metabolism
  • Pancreas / pathology
  • Pancreas, Exocrine / drug effects
  • Pancreas, Exocrine / metabolism*
  • Pancreas, Exocrine / pathology
  • Parenteral Nutrition, Total / adverse effects*
  • Rats
  • Rats, Sprague-Dawley


  • Chaperonin 60
  • Enzyme Precursors
  • Glucagon-Like Peptide 2
  • HSC70 Heat-Shock Proteins
  • HSP27 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Hspb1 protein, rat
  • Neoplasm Proteins
  • Lipase
  • Amylases