LIPID PEROXIDATION IN THE CORTEX OF THE BRAIN OF RATS WITH DIFFERENT STRESS RESISTANCE ON THE COURSE OF EXPERIMENTAL HEMORRHAGIC STROKE
Ivannikova N.O., Koplik E.V.
P. K. Anokhin Science Research Institute of Normal Physiology RAMS, Moscow, Russia. firstname.lastname@example.org
This work was designed to study the changes of lipid peroxidation in the contralateral sensorimotor cortex of the brain in rats with different resistance to stress .on the course of experimental hemorrhagic stroke
Experiments were performed on 45 high-active and low-active (in behaviour in the open field test) Wistar rats. Recently, it has been shown that individuals in a rat population differ in their sensitivity to loading with a similar type of stress. Rats that show greater locomotor’s activity and agility in the open field test are more resistant to acute stress exposure in comparison with less active rats (Koplik et al. 1995; Sudakov 1998).
The control rats were subjected to sham operation for hemorrhagic stroke 1 day before the start of study. The hemorrhagic insult was made by injection 60 mkl of an own blood ( Deinsberger W.1996) in caudate nucleus of the left hemisphere. In 1 day, 3 and 7 day after the operation for animal researched the neurological status (scale Menzes), test of animals behavior in a corner and test of a legs preference (Beliaeva, 2003).
The animals were sacrificed in 1 day, 3 and 7 day after the operation and neurologic inspection. Removed the brain and took samples of tissue (cerebral cortex of the right hemispheres), which were frozen in liquid nitrogen and stored at -30 °C for further biochemical studies. The content of malondialdehyde (MDA) in the sensorimotor cortex of the brain was determined by the method Bowly. MDA content and catalase counted on 1 mg of protein.
Individual behavioral characteristics of rats in the open-field test reflect their resistance to emotional stress and determine the severity of neurological disorders during intracerebral hemorrhage. Stress-resistant rats are characterized by a more rapid restoration of neurological status and disappearance of locomotor and coordination disturbances on day 7 after unilateral hemorrhagic stroke in the caudate nucleus (as compared to stress-predisposed animals).
The experiments demonstrated third day as the most difficult period of hemorrhagic stroke in behaviorally low-active rats. During this period, a sharp increase in the concentration of MDA and a small decline in the antioxidant defense - catalase.
It is established decrease index of lipid peroxidation - MDA and increase the antioxidant catalase in behaviorally high-active (stress-resistant) rats, compared with behaviorally low-active (stress-predisposed) rats on day 7 after hemorrhagic stroke. This indicates a stable system of antioxidant protection, prevents damage, which can cause pathogenic effects of hemorrhagic stroke. It is possible that the lower values of MDA are the determining factor in the increased resistance to emotional stress, which can be explained by the more efficient operation of the antioxidant system .