Proceedings of The Physiological Society
University of Cambridge (2008) Proc Physiol Soc 11, PC58
Exploration of the biochemical processes in rat gastric mucosa under the experimental ulceration.
I. Rudenko1, V. Kovalyova1, L. Ostapchenko1
1. Biological, National Taras Shevchenko University, Kyiv, Ukraine.
World statistics says that stomach ulcer is still one of the most common diseases in the many European countries. On the cell level an important role in ulcer development play violations in the system of the biochemical processes. The aim of this study was to explore biochemical processes in the cells of the stomach gastric mucosa in rats under different models of experimental ulceration. Wistar rats 150 grams weight were used in the experiment. The research were carried out using the aspirin (acetate), stress and ethanol methods of experimental ulceration. To induce stressful ulceration we used social immobilizing stress (Groisman, Carevina). Ethanol ulceration was induced by administration of 1 ml of 80% ethanol per os. To induce acetate ulceration we administered aspirin in doze of 150 microliters per kilogram of body weight 5 times a day during 3 days. A complex exploration of the state of the plasma membranes of rat gastric mucosal cells under different models of ulceration was carried out. It was proven, that lipid peroxidation (LPO) processes play key role in ulcer development irrespective from the factors of ulceration. Under all explored conditions, the LPO products content in the homogenate of gastric mucosa was increased, while an activity of antioxidant enzymes was decreased. A decreased content of all groups of phospholipids was found in plasma membrane fraction. The most significant changes were found under stress - in 2 times. Cholesterol content was increased under stress and ethanol more than in 2 times. Decreased activity of membrane-associated enzymes was also found under ethanol and stress: Na-K ATPase, 5’ nucleotidase, (in 1.8 times under ethanol, in 1.5 times under stress) and Ca-Mg ATPase (in 1.4 times under ethanol, the activity of this enzyme under stress is almost undetectable). Under aspirin there were no significant changes in the activity of these enzymes. Exploration of protein kinases activity showed wide variety of changes. Activity of cyclic adenosine monophosphate-, cyclic guanosine monophosphate-, calcium-, and phospholipid-dependent protein kinases and tyrosine kinase activities were evaluated. Under aspirin ulceration activity of all explored protein kinases was decreased in 1.4 times, activity of PK-G showed no changes. Under ethanol was determined increased activities of PK-A, PK-G and decreased activity of tyrosine protein kinase. Increased activity of all explored protein kinases under stress was also found. This study indicates that stomach ulcer is a complex disease, which leads to different changes in biochemical pathways. Plasma membranes and membrane-associated enzymes and molecules are involved in the ulcer development. Different factors of ulceration lead to changes in different signal transduction pathways.
Where applicable, experiments conform with Society ethical requirements