Short-term effect of adrenalin on S-100b and N-CAM level in the different rat brain areas

Abstract

The level of adrenalin grows under stress conditions, sense of danger, anxiety, fear, trauma, burns and shock. In high concentrations adrenaline increases the speed of protein catabolism. Working through the circulatory system, adrenaline affects almost all the functions of organs, causing the body mobilization to counter stressful situations. Due to ELISA the astrocytes-specific protein (S-100b) and neural cell adhesion molecule (N-CAM) were studied. S-100b is produced mainly by astrocytes іn the brain and depending on the concentration it causes trophic or toxic effect on the neurons and glial cells.Strong stress and ischemia induce re-distribution of calcium-binding protein S-100b and elevation of its level. Quantitative changes of S-100b under the influence of various factors on the body which lead to the metabolic disorder in the brain are considered today as a sign of brain damage (cortical, ischemic one, etc.). Fluctuations in the concentration of S-100b in the brain are not always accompanied by marked deterioration of the physical condition of animals, but they can also lead to a number of violations of integrative functions of the brain depending on over-production of this protein. Most N-CAM are transmembrane proteins that cross the plasma membraneonce; intracellular domains have different size and it is thought they are involved in binding to cytoskeleton or cell signaling. Violation of N-CAM functions leads to disruption of nerve sprouts. Data obtained in our study showed no serious re-distribution of S-100b and N-CAM level in the different areas of rat brain (cerebral cortex, hippocampus and thalamus) under effect of adrenalin administered to the animals (under skin) in dosage of 0.45–0.60 mg per rat, 1 time per day during 10 days, probably because of the type of injection and/or short time of adrenalin action. Increased dosage of adrenaline 1 hour before decapitation leads to the decrease of level of total protein in membrane fraction extracted from brain tissue without changing the level of S-100b and N-CAM.