Effect of portal vein occlusion on the pancreas: an experimental model.
BACKGROUND
The effects of portal vein occlusion on the pancreas are not clearly understood. Therefore, we studied histomorphological changes induced in the rat pancreas by various periods of portal vein occlusion.


METHODS
Sixty female Wistar albino rats were randomly allocated into four groups of 15 each. In Group I (control), rats underwent sham laparotomy to expose the portal vein proximal to its bifurcation. In Groups II-IV, rats underwent laparotomy followed by portal vein occlusion by clamping for 15, 30, and 60 minutes respectively. The pancreas was removed immediately after sham laparotomy in Group I and immediately after clamp release in Groups II-IV. Pancreatic tissue specimens were subjected to histochemical analysis for cell typing and diagnosis, immunohistochemical analysis for identification of the inflammatory markers tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), endothelial nitric oxide synthase (eNOS), and inducible NOS (iNOS), and TUNEL analysis was carried out for identification of apoptotic cells.


RESULTS
Histochemistry revealed signs of inflammation in pancreatic tissue from rats subjected to portal vein occlusion. Immunohistochemistry revealed that the expression of proinflammatory cytokines TNF-alpha and IL-1beta and the oxidative damage indicator iNOS in rat pancreatic tissue increased progressively with the duration of portal vein occlusion. TUNEL assay revealed no signs of apoptosis in any of the groups.


CONCLUSIONS
We conclude that portal vein occlusion triggers an inflammatory response in the pancreas that worsens the longer the occlusion lasts.
Aydede
Hasan
H
Department of Surgery, Celal Bayar University Medical Faculty, Manisa, Turkey. hasanaydede@hotmail.com
Erhan
Yamac
Y
Ikgül
Ozer
O
Cilaker
Serap
S
Sakarya
Aslan
A
Vatansever
Seda
S
D000818:Animals; D017209:Apoptosis; D003251:Constriction, Pathologic / Q000503:physiopathology; D005260:Female; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D053583:Interleukin-1beta / Q000032:analysis; D052247:Nitric Oxide Synthase Type II / Q000032:analysis; D052250:Nitric Oxide Synthase Type III / Q000032:analysis; D010179:Pancreas / Q000378:metabolism / Q000473:pathology*; D010195:Pancreatitis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D011169:Portal Vein / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III