Therapeutic effect of dexamethasone in experimental head injuries

Experimental head injuries, which are easily reproducible in animal studies with guinea pigs, result in a significant increase of secondary serum enzymes. Malate dehydrogenase (MDH), fructose 1,6-diphosphate-aldolase and lactate dehydrogenase (LDH), together with the isoenzymes 1 and 2, are found especially in brain in large amounts. These enzymes act as 'tracer substances' of cerebral tissue and show significantly increased serum activities in cases where acute substantial damage to the brain associated with severe alterations of the blood-brain barrier is found. In the absence of shock, hypoxia and additional bodily injuries the loss of brain tissue has to be considered the only source of enzyme outflow. The early treatment of injured animals with high doses of dexamethasone results in a protective and stabilizing effect, preventing the extrusion of enzymes from the traumatically involved brain cells. Thus by observing the characteristic serum enzyme activities of treated and untreated injured animals a therapeutic effect of dexamethasone can be demonstrated within a relatively short time.