Effect of emotional stress on hemoglobin oxygen affinity in low resistant animals under normal conditions and during cerebral ischemia

Hemoglobin oxygen affinity within the estimated physiological range plays an adaptive antioxidant role during acute cerebral ischemia. This range depends on individual emotional resistance. Brain ischemia induced by common carotid artery occlusion in low resistant Wistar rats increased hemoglobin oxygen affinity by 12% during the acute period. Emotional stress also increased hemoglobin oxygen affinity and determined shifts in this parameter during the development of cerebral ischemia: moderate increase in hemoglobin oxygen affinity (<25%) was followed by further increase in this parameter, while more pronounced shift (>25%) resulted in a significant drop in this parameter due to hemoglobin deoxygenation. Adaptation to stress shifted the upper physiological limit for self-regulation of this process.