Original Article
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World J Gastroenterol. Jul 14, 2012; 18(26): 3379-3388
Published online Jul 14, 2012. doi: 10.3748/wjg.v18.i26.3379
Acute pancreatitis in aging animals: Loss of pancreatitis-associated protein protection?
Sophia Fu, Albert Stanek, Cathy M Mueller, Nefertti A Brown, Chongmin Huan, Martin H Bluth, Michael E Zenilman
Sophia Fu, Albert Stanek, Cathy M Mueller, Nefertti A Brown, Chongmin Huan, Department of Surgery, SUNY Downstate Medical School, Brooklyn, NY 11203, United States
Martin H Bluth, Department of Pathology, Wayne State University, Detroit, MI 48202, United States
Michael E Zenilman, Department of Surgery, Johns Hopkins School of Medicine and SUNY Downstate School of Public Health, Bethesda, MD 20814, United States
Author contributions: Fu S and Stanek A contributed equally; Huan C, Bluth MH and Zenilman ME designed research; Fu S, Stanek A, Mueller CM and Brown NA performed research; Fu S, Stanek A and Zenilman ME analyzed data; Fu S and Zenilman ME wrote the paper.
Correspondence to: Michael E Zenilman, MD, Department of Surgery, Johns Hopkins School of Medicine and SUNY Downstate School of Public Health, 8600 Old Georgetown Road, Bethesda, MD 20814, United States. mzenilm1@jhmi.edu
Telephone: +1-301-8963509 Fax: +1-301-8971330
Received: May 2, 2011
Revised: July 28, 2011
Accepted: May 12, 2012
Published online: July 14, 2012
Abstract

AIM: To investigate the effect of age on severity of acute pancreatitis (AP) using biochemical markers, histology and expression of the protective pancreatitis-associated proteins (PAPs).

METHODS: AP was induced via intraductal injection of 4% sodium taurocholate in young and old rats. Sera and pancreata were assayed at 24 h for the parameters listed above; we also employed a novel molecular technique to assess bacterial infiltration using polymerase chain reaction to measure bacterial genomic ribosomal RNA.

RESULTS: At 24 h after induction of AP, the pancreata of older animals had less edema (mean ± SE histologic score of young vs old: 3.11 ± 0.16 vs 2.50 ± -0.11, P < 0.05), decreased local inflammatory response (histologic score of stromal infiltrate: 3.11 ± 0.27 vs 2.00 ± 0.17, P < 0.05) and increased bacterial infiltration (174% ± 52% increase from sham vs 377% ± 4%, P < 0.05). A decreased expression of PAP1 and PAP2 was demonstrated by Western blotting analysis and immunohistochemical staining. There were no differences in serum amylase and lipase activity, or tissue myeloperoxidase or monocyte chemotactic protein-1 levels. However, in the most-aged group, serum C-reactive protein levels were higher (young vs old: 0.249 ± 0.04 mg/dL vs 2.45 ± 0.68 mg/dL, P < 0.05).

CONCLUSION: In older animals, there is depressed PAP expression related to a blunted inflammatory response in AP which is associated with worsened bacterial infiltration and higher C-reactive protein level; this may explain the more aggressive clinical course.

Keywords: Acute pancreatitis, Aging, Rats, Pancreatitis-associated protein, Molecular biology