AIM:To determine the effects of high osmolarity contrast media (HOCM) and iso-osmolar contrast media (CM) application, with or without pressure, on hepato-pancreato-biliary (HPB) system.METHODS: Sixty rats were divided into six equal groups as follows: Group 1: (0.9% NaCl, control), Group 2: (diatrizoate meglumine Na, ionic HOCM, Urographin?), Group 3: (iodixanol, iso-osmolar non-ionic CM, Visipaque?); each of which was applied without pressure, whereas the animals of the remaining three groups (1p, 2p, 3p) were subjected to the same CM with pressure. We performed a duodenal puncture and introduced a catheter into the ampulla. After the catheterization, 0.2 mL CM or 0.9% NaCl was injected with or without pressure. Blood samples were taken for biochemical evaluations. The histopathological examinations of liver, common bile duct, and pancreas were performed.RESULTS: There were no significant differences between the six groups for blood amylase, alanine aminotransferases, aspartate aminotransferases, bilirubin levels (P>0.05). Alkaline phosphatase and γ glutamyl transaminase levels were higher (P < 0.05) in the Urographin? groups (2, 2p) than the Visipaque? groups (3, 3p), or control groups (1, 1p). Hepatocyte necrosis, portal area inflammation, and Kupffer’s cell hyperplasia were higher (P<0.05) in the study groups than the control group. However, there were no significant differences (P>0.05) between HOCM (2,2p) and iso-osmolar CM (3,3p) groups. Bile duct proliferation and regeneration in the Urographin groups (2, 2p) were significantly higher (P<0.05) than the Visipaque groups (3, 3p) or the control groups (1,1p). Although CM caused minor damage to the pancreas, there were no statistically significant differences (P>0.05) between the groups. Application of the CM with pressure did not cause additional damage to the HPB system.CONCLUSION: Iso-osmolar, non-ionic CM could be more reliable than the ionic HOCM, whereas the application of pressure during the CM application had no effect on the HPB system. AIM: To determine the effects of high osmolarity contrast media (HOCM) and iso-osmolar contrast media (CM) application, with or without pressure on hepato-pancreato-biliary (HPB) system. METHODS: Sixty rats were divided into six equal Group 2: (diatrizoate meglumine Na, ionic HOCM, Urographin®), Group 3: (iodixanol, iso-osmolar non-ionic CM, Visipaque®); each of groups which was applied without pressure, while the animals of the remaining three groups (1p, 2p, 3p) were subjected to the same CM with pressure. We performed a duodenal puncture and introduced a catheter into the ampulla. After the catheterization, 0.2 mL CM The histopathological examinations of liver, common bile duct, and pancreas were performed .RESULTS: There were no significant differences between the six groups for blood amylase, alanine or 0.9% NaCl was injected with or without pressure aminotransferases, aspartate amino transfected bilirubin levels (P> 0.05). Alkaline phosphatase and γ glutamyl transaminase levels were higher in the Urographin groups (2, 2p) than the Visipaque groups (3, 3p) , 1p). Hepatocyte necrosis, portal area inflammation, and Kupffer’s cell hyperplasia were higher (P <0.05) in the study groups than the control group. Bile duct proliferation and regeneration in the Urographin groups (2, 2p) were significantly higher (P <0.05) than the Visipaque groups (3, 3p) or the control groups ( There was no significant significant differences (P> 0.05) between the groups. Application of the CM with pressure did not cause additional damage to the HPB system. CONCLUSION: Iso-osmolar , non-ionic CM could be more reliable than the ionic HOCM, while the application of pressure during the CM ap plication had no effect on the HPB system.