Trace elements, cholesterol and ultrastructural alterations of aorta in hypodynamic stress]

Hypodynamic stress of 48-day duration was provoked by permanent and periodically recurrent intervention (the hypodynamics periodically exchanged to physically activity) for Chinchilla rabbits (weight 2.5-3.0 kg) (n=19) by placing them in metal hutches according to B. V. Fiodorow. Rabbits (n=10) of the control group which had no intervention were kept in vivarium conditions. The concentration of trace elements (Zn, Mn, Cu) in the blood plasma and thoracic aorta was assessed by atomic absorption spectrophotometer (Perkin-Elmer 503, USA). The level of cholesterol was determined by enzymatic analysis. Ultrathin sections of thoracic aorta were examined with electron microscope "Tesla BS-500" (Italy). After 48 days of permanent hypodynamic stress the concentration of Zn and Mn in blood plasma of rabbits was found to be significantly decreased while the cholesterol and Cu level was greater than before the stress. In case of permanent stress significant decrease also was found in the concentration of Cu and Mn in aorta in comparison with that in the case of periodically recurrent stress. The mentioned changes of the trace elements and cholesterol concentration in tissues of rabbits in case of permanent hypodynamic stress were accompanied by ultrastructural alterations in endothelium--desintegration of cells, and winding and fragmentation of internal elastic lamina, accumulation of lipids. In case of periodically recurrent hypodynamic stress of the some duration these changes were less expressed.