THE INFLUENCE OF INCREASED INTRA-ABDOMINAL PRESSURE ON THE INTENSITY OF LIPID PEROXIDATION PROCESSES IN THE LUNGS OF RATS OF DIFFERENT AGE GROUPS

Abstract

Introduction. Laparoscopic cholecystectomy has become the main low-invasive surgical intervention in case of acute calculous cholecystitis. Among all patients with complications of gastrointestinal tract pathology, acute calculous cholecystitis is reported in 42–50 % of elderly and geriatric patients. Despite the safety of the method, some publications note the need for careful performance of laparoscopic cholecystectomy in elderly patients, due to transient physiological changes in the body, which causes an increase of pressure in the abdominal cavity. However, the age-related peculiarities of the influence of increased intra-abdominal pressure on the activity of lipid peroxidation processes in the lungs, an organ that is sensitive to external or internal interventions, remain insufficiently studied.

The aim of the study – to determine the influence of increased intra-abdominal pressure on the intensity of lipid peroxidation processes in the lungs in rats of different age groups.

Research methods. In the experiments, 70 white male Wistar line rats of two age groups were used: mature rats aged 6-8 months and weighing 180–200 g and old rats aged 19–23 months and weighing 300–320 g. An abdominal cavity was catheterized under conditions of thiopental sodium anesthesia and atmospheric air was inflated with a manual insufflator to an intra-abdominal pressure of 20 mm Hg. The exposure time was 60 min. The rats were taken out of the experiment immediately after decompression of the abdominal cavity, as well as after 1, 3 and 7 days. The content of lipid peroxidation products: diene and triene conjugates (DC, TC) and thiobarbituric acid reagents (TBA-active LPO products) was determined in 10 % extract of lung homogenate.

Results and Discussion. The increase of pressure in the abdominal cavity caused an intensification of LPO processes in the lungs of rats of different ages, which was manifested by an increase in the concentration of primary and secondary products in the lung homogenate extract with a maximum after 1 day of abdominal decompression. The content of primary products, in particular TС, in the lungs was significantly higher in the group of mature rats immediately after decompression of the abdominal cavity and after 1 and 7 days of the experiment, while the content of secondary products, in particular TBA-active products, was higher in the group of old rats at all studied times after decompression. The degree of TC increase in the lungs was significantly higher in the group of mature rats after 1 day of the experiment, and in the group of old rats – after 7 days. The degree of increase in the content of
TBA-active lipid peroxidation products in the lungs after 1 and 3 days of the experiment was significantly higher in mature rats. These results indicate the advisability of antioxidant replacement therapy during laparoscopic interventions with increased intra-abdominal pressure in the older age group.

Conclusions. Under conditions of increased intra-abdominal pressure to 20 mm Hg with an exposure of 1 hour, an increase in lipid peroxidation processes is observed in the lungs of mature and old rats, which is manifested by an increase in the content of DC, TC and TBA-active lipid peroxidation products with a maximum 1 day after decompression and a subsequent decrease by the 7th day of the experiment. The degree of increase of the studied lipid peroxidation parameters after abdominal cavity decompression was significantly higher in the group of mature rats than in the old ones.