Investigation of ER stress level in experimental pancreatitis and hyperlipidemia models created in rats

Objective: Acute pancreatitis is an inflammatory disease whose pathophysiology has not been fully elucidated and may only be treated with mild symptoms such as abdominal pain or may result in mortality. Many etiological factors such as hypertriglyceridemia can cause pancreatitis. Hypertriglyceridemic pancreatitis may be more severe than pancreatitis. Again, the pathophysiology of hypertriglyceridemic pancreatitis has not been fully revealed. Endoplasmic reticulum stress occurs as a result of the accumulation of misfolded or unfolded proteins. In this case, a coping mechanism called the unfolded protein response (UPR) comes into play. A connection between UPR and pancreatitis and hyperlipidemia has been shown. In our study, we wanted to reveal the effect of hyperlipidemia on tissue damage in the pancreas with pancreatitis and its connection with endoplasmic reticulum stress. Materials and methods: In our study, we created four groups with thirty-two Sprague-Dawley rats, with eight animals in each group. In rats, hyperlipidemia was caused by poloxomer-407, pancreatitis was caused by cerulein and hyperlipidemic pancreatitis was caused by both applications. Rat pancreatic tissues were evaluated by applying hematoxylin and eosin staining and light microscopic scoring. Pancreatic tissues were evaluated visually by immunohistochemically applying GRP78, IRE-1, XBP-1 antibodies. GRP78, IRE-1α, sXBP-1 mRNA values were evaluated relatively by qPCR. Results: It was found that pancreatic damage in the hyperlipidemic pancreatitis group was greater than in the pancreatitis group. While the amount of GRP78 mRNA was found to be relatively higher in the hyperlipidemic pancreatitis group than in the pancreatitis group, this difference was not significant. Clear expression of IRE-1α and sXBP-1 genes could not be revealed for all groups. The images obtained by immunostaining were parallel to the PCR results. Conclusion: It was revealed that hyperlipidemia is a condition that increases pancreatic damage in pancreatitis, but no significant difference could be detected in terms of ER stress markers between the pancreatitis and hyperlipidemic pancreatitis groups.