Sodium and potassium content of brain and muscle of rats subjected to high acceleration

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

Male Albino (Wistar) rats were subjected to a radial acceleration stress on an eight-foot centrifuge. Each centrifugation of 20 positive g (head to foot) lasted 20 seconds followed by a 1-minute rest period. The stress pattern consisted of 40 exposures to this sublethal stress in approximately 1 hour. The entire brain and a section of the rectus femoris muscle were removed and analyzed for their sodium and potassium content. There was a significant decrease in muscle and brain potassium and a significant increase in muscle sodium; brain sodium remained unchanged. In one series of rats a sublethal intraperitoneal injection of sodium amytal was given 3 minutes prior to decapitation. In contrast to the unanesthetized series, this group showed an increase in brain potassium in the stress animals.