Background: Previous findings have demonstrated that activation of polyamine catabolism in transgenic rats (over-expressing spermidine/spermine N'-acetyltransferase, SSAT) results in acute pancreatic inflammation, suggesting that depletion of polyamines (spermine and spermidine) may be one step in the evolution of acute pancreatitis. The purpose of this study was to explore this hypothesis in another model, and to study the timing of the changes in the polyamine metabolism in relation to trypsin activation.
Methods: 36 rats (300g~350g) were divided into 2 groups (pancreatitis group and sham group). In pancreatitis group 0.2 ml of 2.0% sodium taurodeoxycholate was infused into the pancreatic duct. In sham group the animals underwent laparotomy only. All animals were sacrificed and sampled under anesthesia at 3h, 24h and 48h. 6 rats served as 0 hour controls without operation. Serum amylase and pancreatic SSAT activities were measured. Pancreatic histology, water content and concentrations of spermine, spermidine and trypsin activation peptide (TAP) were analysed. Results: In the pancreatitis group with hyperamylasemia, pancreatic edema, and pancreatitis histology SSAT was induced early, in association with trypsin, resulting in substantial decrease of both spermine and spermidine (Table). Pancreatic SSAT activity and TAP content correlated with each other (correlation coefficient 0.782, P<0.05).Group | Parameters | 0 h (controls) | 3 hours | 24 hours | 48 hours |
pancreatitis group | Amylase (U/I) | 1915±138 | 8013±935* | 11292±2097 | 3867±925 |
SSAT (pmol/mg protein/10min) | 4,2±0,2 | 56,4±13,8 | 13,8±5,3 | 4,7±0,9 | |
TAP (pmol/mg protein) | 7,2±1,2 | 71,6±11* | 25,3±4,7 | 9±4,3 | |
Spermidine (pmol/mg protein) | 1646±27 | 1023±188 | 660±155* | 1478±195 | |
Spermine (pmol/mg protein) | 189±6 | 170±15 | 132±7* | 205±28 | |
sham group | Amylase (U/I) | 1915±138 | 2685±202 | 6436±1240 | 2836±399 |
SSAT(pmol/mg protein/10min) | 4,2±0,2 | 8,4±2,1 | 7,5±0,7 | 7,0±1,9 | |
TAP(pmol/mg protein) | 7,2±1,2 | 9,6±3,4 | 10,1±2,2 | 4,4±0,7 | |
Spermidine(pmol/mg protein) | 1646±27 | 1489±22 | 1259±86 | 1310±234 | |
Spermine(pmol/mg protein) | 189±6 | 194±7 | 183±14 | 209±8 |