International Journal ofPancreatology, vol. 22, no. 3, 193-200, December 1997 9 Copyright 1997 by Humana Press Inc. All rights of any nature whatsoever reserved. 0169 -4197/97/22:193-200/$10.00 Spontaneous and Cholecystokinin-Octapeptide-Promoted Regeneration of the Pancreas Following L-Arginine-Induced Pancreatitis in Rat P ter Hegyi,* Tam(ts Tak(tcs, Katalin Jdrmay, Istvdn Nagy, L(tszl6 Czak6, and Jdnos Lonovics First Department of Medicine, Albert Szent-Gy6rgyiMedical University, Szeged, Hungary Summary Conclusion. In L-arginine (Arg)-induced pancreatitis, evidence of acute inflammation was observed on d 1-3. Continuous tissue atrophy became visible at the sites of previous pancreatic necrosis, with simultaneous regeneration of the pancreas, mainly around the Langerhans islets. Administration of low doses of cholecystokinin-octapeptide (CCK-8) increased the inflammatory signs of pancreatitis in the early phase, but subsequently diminished the level of atrophy and accelerated the processes of regen- eration in this model of pancreatitis. Background. The aim of this work was to study the regenerative processes following Arg-induced pan- creatitis in rats. Besides the spontaneous regeneration, the effects of low doses of CCK-8 on the laboratory and morphologic parameters in this type of experimental pancreatitis were investigated. Methods. Male Wistar rats were divided into three groups. In group I, the rats received 200 rag/100 g body weight of Arg ip twice, at an interval of 1 h, and 0.5 mL saline was administered sc twice daily. In group II, besides the same amount of Arg, the rats received 1 gg/kg of CCK-8 sc in 0.5-mL saline twice daily (7 AMand 7 pM). In the control animals (group III), an identical amount of glycine was administered ip instead of Arg at the same times. The rats were examined on d 1, 3, 7, 14, and 28 after pancreatitis induction. The pancreatic weight/body weight ratio (pw/bw) was calculated in each case. The serum levels of amylase, and glucose and the pancreatic contents of soluble protein, trypsin, amylase and DNA were determined, and histologic exami- nations were performed. Results. In groups I and II, both pw/bw (3.5 + 0.2 mg/g and 4.1 + 0.28 mg/g, respectively) and the serum amylase level (8900 + 560 IU/L and 11100 + 1390 IU/L, respectively) were significantly elevated on d 1 vs group III (2.1 + 0.06 mg/g and 5562 + 373 IU/L, respectively). Pw/bw was significantly decreased in groups I (0.96 + 0.12 rag/g, 0.8 +_ 0.1 mg/g, and 1.8 + 0.1 rag/g, respectively) and II (1.4 + 0.15 mg/g, 1.7 + 0.2 mg/g, and 1.95 + 0.1 mg/g, respectively) on d 7, 14, and 28 vs group III (2.6 + 0.3 mg/g, 3.1 + 0.15 rag/g, and 2.7 + 0.1 mg/g, respectively), whereas in group II it was significantly elevated vs. group I on d 7 and 14. The pancreatic contents of soluble protein, DNA, trypsin and amylase were significantly decreased on d 3-14 in groups I and II vs group III. The pancreatic DNA level was significantly elevated in group II (1.23 + 0.2 mg/pancreas) vs group I (0.7 + 0.1 rag/pancreas) on d 7. In group II, the soluble protein (73.1 + 15.5 mg/pancreas) and amylase (1104 + 160 IU/pancreas) levels were significantly elevated on d 14 as was that of trypsin (27.2_+3.1 IU/pancreas) on d 28, vs group I (26.4 + 5.3 mg/p, 525 + 111 IU/pancreas, and 16.3 + 1.1 IU/pancreas, respectively). On Received January 22, 1997; Revised June 11, 1997; Accepted June 11, 1997. *Author to whom all correspondence and reprint requests should be addressed: First Department of Medicine, Albert Szent-Gy6rgyi Medical University, Szeged H-6701, PO Box 469, Hungary. 193