ANTIOXIDANT-PROOXIDANT BALANCE OF THE LIVER IN THE DYNAMICS OF CRANIO-SKELETAL TRAUMA IN RATS OF DIFFERENT AGES

Abstract

Introduction. The rise in the level of injuries is a characteristic feature of the third millennium and affects victims of all age groups. In conditions of cranio-skeletal trauma (CST), traumatic shock occurs, significantly impairing the blood supply to organs and tissues located far from the site of direct injury, including the liver, which contributes to deepening hypoxia, increased generation of reactive oxygen forms and pro-inflammatory mediators. The antioxidant defense is compensatory activated, which is aimed at maintaining antioxidant-prooxidant homeostasis.

The aim of the study – to determine the dynamics of antioxidant-prooxidant balance in the liver of different aged rats under conditions of experimental cranio-skeletal trauma.

Research Methods. In the experiments, 147 white male Wistar line rats of different age groups were used. The first experimental group included immature animals aged 100–120 days. The second group included mature animals aged 6–8 months. The third group included old animals aged 19–23 months. In all experimental groups, CST was modeled under conditions of thiopental sodium anesthesia. Control rats were only injected with thiopental sodium anesthesia. Animals were taken out of the experiments in the conditions of anesthesia after 1, 3, 7, 14, 21 and 28 days by the method of total bleeding from the heart. Catalase activity and the content of thiobarbituric acid reagents were determined in a 10 % liver homogenate extract, and the antioxidant-proliferative index (API) was calculated from the ratio of these two factors.

Results and Discussion. Under the influence of CST in rats of different ages, compared with the control, from 1–28 days of the posttraumatic period, the value of API significantly decreased. In immature rats, the index reached a minimum value after 7 days and gradually increased up to the 28^th day; in mature and old rats, the index reached a minimum value after 3 days of the post-traumatic period, remained at the same level until the 14^th day with further increase. The API value at all studied terms of the posttraumatic period was significantly lower in old rats compared to rats of other experimental groups, and after 1, 3, 21, and 28 days of the experiment – in mature rats compared to immature rats. The degree of API reduction at terms of the posttraumatic period was significantly greater in the group of old rats compared to other experimental groups. The revealed age difference in the development of oxidative stress in response to CST indicates a lower antioxidant capacity of old rats under conditions of trauma and requires additional antioxidant therapy. 

Conclusions. The modeling of CST in rats of different age groups is accompanied by the development of oxidative stress, as evidenced by a decrease in liver API compared to the control, which in immature rats becomes minimal after 7 days of the experiment, in mature and old rats – after 3–14 days with a subsequent increase until the 28^th day, which does not reach the control level. At all periods of the post-traumatic period, the degree of decrease in the API value in old rats is significantly higher than in immature and mature rats.