The proposed project involves a collaborative biochemical and morphological study of some aspects of the aging process in human erythrocytes. It is planned to study the effects of agents which induce the peroxidation of unsaturated fatty acids in membrane phospholipids. In particular, the effects of ethylene and ethane generated during the peroxidation process will be investigated. It is postulated that ethylene and ethane generated by endogenous or exogenous peroxidation-initiators may have important biological actions in mammalian cells. The methods to be used include freeze etching, scanning microscopy, and spectrophotometric determinations of membrane enzyme components related to red cell function and survival.