ISCHEMIA - INDUCED DISTURBANCES OF POLYAMINE SYNTHESIS

Publisher Summary This chapter discusses ischemia-induced disturbances in polyamine synthesis. It discusses the periods of time during which changes take place and the relationship of changes in polyamine synthesis to the duration of ischemia. Pharmacological interventions reducing ischemia-induced disturbances in polyamine synthesis are discussed. Emphasis is put on the possible role of ischemia-induced alterations in polyamine metabolism in the process of recovery from the metabolic stress produced either by cerebral ischemia or in the manifestation of neuronal necrosis. Transient cerebral ischemia causes a disturbance of polyamine synthesis that is characterized by a sharp increase in ornithine decarboxylase and decrease in S-adenosylmethionine decarboxylase activity. The result is an overshoot in putrescine formation and a reduction in spermine levels. In addition, evidence is presented that polyamines are released from the intracellular compartment during ischemia and following prolonged recirculation in severely damaged areas. Because of the main features of ischemia-induced disturbances in polyamine synthesis and the reactions known to be influenced by these altered polyamine profiles it is suggested that these changes play a role in the manifestation of ischemia-induced neuronal necrosis.