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Protein malnutition‐induced exocrine pancreas dysfunction
Author(s) -
Crozier Stephen J,
Ginsburg Lauren E,
Ernst Stephen A
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a837
Subject(s) - medicine , pancreas , endocrinology , zymogen , exocrine pancreas , ribosomal protein s6 , phosphorylation , atrophy , biology , chemistry , protein phosphorylation , enzyme , protein kinase a , microbiology and biotechnology , biochemistry
Protein malnutrition results in exocrine pancreas dysfunction, but very little is known regarding the underlying mechanisms. To model protein malnutrition and recovery, mice were fed isocaloric protein‐free chow (PFC) for 4 days and then returned to control chow (CC). After 4 days on PFC, the mass of the pancreas decreased by 33% when corrected for changes in body mass. When returned to CC for 4 days, pancreatic mass increased to 95% of its initial value. Pancreatic protein content decreased by 60% after 4 days on PFC and then returned to control values after 4 days on CC, while there were no changes in pancreatic DNA content. Histology revealed significant cellular atrophy and loss of zymogen granules after 4 days on PFC. Changes in pancreatic mass, protein synthetic rates, and chymotrypsin concentration corresponded with changes in the phosphorylation of downstream effectors of the mTOR pathway. Phosphorylation of ribosomal protein S6 and 4E‐BP1 decreased in the pancreas after 4 days on PFC, but was greater than control values after 1 day on CC and returned to control values after 4 days. These results demonstrate that protein biosynthesis is impaired in the pancreas of mice fed PFC, but quickly recovers when protein is returned to the diet. These changes appear to be modulated by activation of the mTOR pathway. This work was supported by grant NIH DK59578.