EFFECTS OF HIGH ACCELERATORY FORCES AND THEIR ALLEVIATION

Abstract

A centrifuge for subjecting laboratory animals to acceleratory forces is described. Guinea pigs and rats were observed to be the most resistant of the various mammalian species tested, the lethal limit for [male] rats being about 50 g-min. [male] animals were able to tolerate higher g-min. values than were [male][male]. Castration tests did not explain this difference. Estrus activity was inhibited in the rat by exposure to g. Increasing tolerance to g was exhibited by rats and dogs on repeated exposure, especially over a period of mos. A high degree of protection was afforded by a simple belt or strap, desoxycorticosterone acetate injn., pressor substances, fasting, and the pre-breathing of CO2. Forced exercise was found to be deleterious, but alcohol ingestion did not affect g-tolerance in the rat. Permanent disorientation and chronic rigidity were interesting conditions observed after severe exposures. "Delta" brain waves were produced on centrifugation, and a sufficiently severe exposure caused all brain waves to cease. In dogs, severe acceleratory shock responded well to amyl nitrite. Hyper -glycemia was commonly observed, liver, muscle and heart glycogen being reduced. Serum electrolytes and water content remained unchanged although some hemoconcn. was seen. The great majority of animals exhibited no significant pathologic lesions after even severe exposures to acceleration.