Volume 119, Issue 5, Pages 1373-1381 (November 2000) Nerve growth factor expression is up-regulated in the rat model of L-arginine–induced acute pancreatitis  Hiroki Toma, John Winston, Maria–Adelaide Micci, Mohan Shenoy, Pankaj J. Pasricha  Gastroenterology  Volume 119, Issue 5, Pages 1373-1381 (November 2000) DOI: 10.1053/gast.2000.19264 Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 1 Serum amylase levels in control (●) and L-arginine–injected (○) rats. Serum levels of amylase were significantly higher up to 1 day, then were lower beginning 2 days after the second injection in L-arginine–injected rats than in control rats. *P < 0.05; **P < 0.01. Gastroenterology 2000 119, 1373-1381DOI: (10.1053/gast.2000.19264) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 2 Paraffin sections of rat pancreas stained with H&E. The pancreas was removed and processed for paraffin embedding at (A) 2 hours, (B) 6 hours, (C) 3 days, and (D) 5 days after either L-arginine or saline treatment. (A and B) Intense vacuolization is observed in acinar cells at 2 and 6 hours in L-arginine–injected rats. (C) The tissue was severely necrotic, with loss of exocrine pancreas at 3 days. (D) Widespread areas of pancreas were replaced by connective tissue with inflammatory cells at 5 days. Bar = 100 mm. Gastroenterology 2000 119, 1373-1381DOI: (10.1053/gast.2000.19264) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 3 Increase in NGF mRNA expression in pancreas from L-arginine–injected rats. (A) RNase protection assay on samples from L-arginine–injected (○) or control rats 2 hours, 6 hours, 3 days, and 5 days after the second injection. The bands corresponding to β-NGF (322 bp) were weak in pancreas from control rats at all time points and in pancreas from L-arginine–injected rats at 2 and 6 hours. The strong signals were obtained in pancreas from L-arginine–injected rats at 3 and 5 days. (B) Normalized NGF mRNA expression as fold increase over control values. The intensities of NGF mRNA bands obtained by RNase protection assay were densitometrically analyzed and normalized by signals of the housekeeping gene, L32. Note the dramatic increase of NGF mRNA expression in pancreas at 3 and 5 days. **P < 0.01. Gastroenterology 2000 119, 1373-1381DOI: (10.1053/gast.2000.19264) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 4 NGF protein levels in control (□) and L-arginine–injected (■) rats. No difference was observed between control and L-arginine–injected rats at 2 and 6 hours. NGF protein levels were higher in pancreas from L-arginine–injected rats than in those from control rats at 3 and 5 days. The difference was statistically significant at 5 days *P < 0.05. Gastroenterology 2000 119, 1373-1381DOI: (10.1053/gast.2000.19264) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 5 Immunohistochemistry for NGF localization in pancreas paraffin sections from control and L-arginine–injected rats. (A) NGF-IR in a cross section of pancreas from a control rat (saline-injected). The intense immunoreactivity is present in the islet of Langerhans (arrow). Bar = 100 mm. (B) Higher-magnification view of the islet of Langerhans from control rat pancreas. NGF-IR is found in the majority of islet cells. Bar = 25 mm. (C) NGF-IR in a cross section of pancreas from an L-arginine–injected rat (2 hours after treatment). NGF-IR is lost in the islet of Langerhans (arrow). Strong immunoreactivity is present in the surrounding parenchyma. Bar = 100 mm. (D) Higher-magnification view of an islet of Langerhans from L-arginine–injected rat pancreas showing loss of NGF-IR in the majority of islet cells. Bar = 25 mm. (E and F) NGF-IR in pancreas paraffin sections from (E) saline-injected and (F) L-arginine–injected rats 5 days after injection. NGF-IR is predominantly associated with pancreatic ducts 5 days after induction of pancreatitis (F, arrow). Bar = 25 mm. Gastroenterology 2000 119, 1373-1381DOI: (10.1053/gast.2000.19264) Copyright © 2000 American Gastroenterological Association Terms and Conditions