Effects of Acceleration on Selected Serum Enzymes

Human volunteers were exposed to 30-second bouts of acceleration at 3, 4, 5, 6, and 7 G at each of three seat back angles on several different experimental days. Blood samples were taken immediately before the experiment and 24 hours later. Samples were analyzed for hematocrit, lactate dehydrogenase, lactate dehydrogenase isoenzyme distribution, creatine phosphokinase, creatine phosphokinase isoenzyme distribution, glutamate oxaloacetate transaminase, and glutamate pyruvate transaminase. None of the assayed biochemical parameters were outside normal clinical limits; however, small but statistically significant increases in creatine phosphokinase in two subjects and increases in lactate dehydrogenase and creatine phosphokinase in the subjects as a group were evident.