Erythrocyte Hydration Under Positive Acceleration

¹ From the U.S. Naval Air Development Center, Aviation Medical Acceleration Laboratory, Johnsville, Pennsylvania

Rhesus monkeys were employed to study the effects of positive acceleration on erythrocyte hydration. Blood samples were obtained from the carotid artery just before and immediately after exposure to a standard pattern of positive g. The mean corpuscular hemoglobin concentration (M.C.H.C.) fell an average of 5.8%. This striking fall in M.C.H.C. indicated that after g exposure the monkey's erythrocytes were greatly increased in size. Fluid had shifted into the red blood cells. There was a mean decrease of 2.3% in the hemoglobin concentration. The hematocrits remained constant during these experiments. A slight decrease in the relative viscosity of the blood was noted; this finding, however, was not statistically significant. Sulfhydryl concentration by itself and in relation to the hematocrit did not show a significant change after acceleration.