Acute pancreatitis in aging animals: loss of pancreatitis-associated protein protection?
OBJECTIVE
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).


CONCLUSIONS
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.
Department of Surgery, SUNY Downstate Medical School, Brooklyn, NY 11203, USA.
Sophia
S
Fu
Albert
A
Stanek
Cathy M
CM
Mueller
Nefertti A
NA
Brown
Chongmin
C
Huan
Martin H
MH
Bluth
Michael E
ME
Zenilman
D000208:Acute Disease; D000375:Aging; D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D002097:C-Reactive Protein / Q000378:metabolism; D023281:Genomics; D007150:Immunohistochemistry / Q000379:methods; D007249:Inflammation; D037181:Lectins, C-Type / Q000096:biosynthesis*; D008297:Male; D010195:Pancreatitis / Q000175:diagnosis* / Q000378:metabolism*; D000073718:Pancreatitis-Associated Proteins; D012335:RNA, Ribosomal / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012270:Ribosomes / Q000378:metabolism; D013656:Taurocholic Acid / Q000494:pharmacology*; D013997:Time Factors
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D037181:Lectins, C-Type; D000073718:Pancreatitis-Associated Proteins; C000612141:REG3A protein, human; D012335:RNA, Ribosomal; C000612146:Reg3a protein, rat; C000612144:Reg3b protein, rat; D013656:Taurocholic Acid; D002097:C-Reactive Protein