الفهرس 
Introduction and aim of workOnly 14 pages are availabe for public view
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Abstract
The present study was conducted to investigate effects of pioglitazone and hemin on AP induced by i.p injection of L-Arginine in rats and whether the combined administation of the two drugs can provide an additional beneficial effect compared to each treatment alone.
In addition, we attempted to elucidate the role of HO-1 induction in the protective effect of pioglitazone against L-Arginine induced pancreatitis.
In the present study, adult male rats were initially divided into two groups, Control group, rats were normal, received only solvent with the same volume and L-arginine-induced AP. 3 days later after induction of AP, L-arginine-induced AP rats were further subdivided into seven groups; each consists of 8 rats, and was given the drug regimen for 3 days.
L-arginine-treated rats were received a single injection of L-arginine in a dose of 750 mg/kg intraperitoneally.
L-arginine + hemin were L-arginine-treated rats received hemin in a dose of 10 mg/kg, i.p for 3 successive days. L-arginine + hemin + ZnPP were L-arginine-treated rats pretreated with ZnPP in a dose of 6.25 mg/kg, i.p prior to hemin injection in a dose of 10 mg/kg, i.p for 3 successive days.
L-arginine + pioglitazone were L-arginine-treated rats received pioglitazone in a dose of 50 mg/kg, orally for 3 successive days.
L-arginine + pioglitazone + ZnPP were L-arginine-treated rats pretreated with ZnPP in a dose of
6.25 mg/kg, i.p prior to pioglitazone in a dose of 50 mg/kg, orally for 3 successive days.
L-arginine + pioglitazone + hemin were L-arginine-treated rats received hemin in a dose of 10 mg/kg, i.p and pioglitazone in a dose of 50 mg/kg, orally for 3 successive days.
L-arginine + pioglitazone + hemin + ZnPP L-arginine-treated rats pretreated with ZnPP in a dose of 6.25 mg/kg, i.p prior to hemin in a dose of 10 mg/kg, i.p and pioglitazone in a dose of 50 mg/kg, orally for 3 successive days.
At the end of experimental period, animals were decapitated, pancreas was excised. Sera were collected and stored at -80˚C till the time of analysis. Prior to analysis, pancreatic tissues were collected in phosphate buffered saline (PBS) and homogenized to prepare homogenates then the supernatant was separated for different analysis.
To achieve these aims, the following experiments in L-arginine-induced AP rats in presence and absence of drug regimen under investigation:
1. Evaluating pancreatic injuries through measurement of serum pancreatic enzymes; amylase and lipase activities.
2. Evaluating the oxidative stress via measuring malondialdehyde (MDA) (an index of lipid peroxidation) in the pancreatic tissue as well as measuring the antioxidant parameter glutathione reductase (GSH).
3. Measuring nitric oxide level (NO) in the pancreatic tissue.
4. Determination of NOX-2, PPAR-γ and COX-2 mRNA level by RT-PCR.
5. Determination of NF-Kβ and HO-1by using W.B in pancreatic tissue.
6. Determination of TNF-α level by ELISA.
7. Histopathological examination of pancreatic specimens taken from each group was made to confirm the results.
8. Immunohistochemical analysis of COX-2 and TGF-β.
The results of the study was clearly demonstrated that rats treated with L-arginine in a dose of
750 mg/kg intraperitoneally leads to pancreatic tissue damage. L-arginine-induced AP was confirmed by histopathological changes in comparison to control group.
Moreover, there was increase in serum levels of pancreatic enzymes (Amylase and Lipase) as they represent the most important diagnostic markers of AP. In addition, an increase in the oxidative stress was detected by increase in MDA and by decrease the activity of antioxidants parameter GSH.
In addition, a significant increase in both NOX-2 and COX-2 mRNA level was observed. the increase in expression of NF-Kβ and TNF-α proteins and increase in NO level refers to the role of these inflammatory cytokines in the pathogenesis of AP. Rats treated with pioglitazone, hemin or their combination showed the following results: marked decrease in serum level of pancreatic enzymes (Amylase and Lipase), MDA level, NO level, NF-Kβ, TNF-α protein level, COX-2, NOX-
2 mRNA level and TGF-β and marked increase in HO-1 protein level, PPAR-γ mRNA level and
GSH level.
Furthermore, the microscopic examination of pancreas of those rats revealed an improvement in histopathological changes.
We conclude from these data that both pioglitazone and hemin given prior to induction of experimental acute pancreatitis results in amelioration of oxidative stress and inflammation. Based on effective inhibition of HO-1 activity induced by ZnPP, this inhibition abolished the protective effect of pioglitazone which indicate that this protective effect of pioglitazone may be mediated at least in part through HO pathway. HO-1 induction may provide an additional treatment option for the management of patients with AP. There was no evidence that intervention with both pioglitazone and hemin (in animals with experimental acute pancreatitis) was associated with either intra-abdominal or intra-pancreatic hemorrhage.
The question of whether those agents can modify the complex clinical course of the human disease remains unanswered and we would caution against over-extrapolation to the clinical setting
from experimental studies. To take this work forward, further experimental studies may be of
benefit. (Melo et al., 2010; Hai et al., 2017).