The content of neuroglobin in neurons of the parietal cortex and hippocampus of rats with cerebral ischemia of varying severity

Abstract

Introduction. The role of neuroglobin ischemia is still unclear. Some studies indicate its neuroprotective effect due to increased expression of endothelial NOS. Other evidence refutes its significance for neuronal survival under oxygen-deficient conditions, as neuroglobin deficiency appears to increase HIF-1α expression. Materials and methods. The experiments were performed on 56 male outbred white rats weighing 258±18 g. Total cerebral ischemia was simulated by decapitation of animals, whereas the subtotal one was simulated by simultaneous ligation of both carotid arteries. Stepwise subtotal cerebral ischemia was performed by ligating both carotid arteries with an interval of 7 days (subgroup 1), 3 days (subgroup 2), or 1 day (subgroup 3). Results. The study found significant differences in neuroglobin content across three subgroups. In subgroup 1, there was a notable increase in neuroglobin content compared to the control group, with a 13% increase in the parietal cortex (p<0.05) and a 14% increase in the hippocampus (p<0.05). However, subgroup 2 showed a decrease in neuroglobin content, with a 13% decrease in the parietal cortex (p<0.05) and a 7% decrease in the hippocampus (p<0.05). The most significant decrease in neuroglobin content was observed in subgroup 3, with a 31% decrease (p<0.05) in the parietal cortex and a 33% decrease (p<0.05) in the hippocampus. In subgroup 3, the parietal cortex showed a 40% decrease in neuroglobin content compared to subgroup 1 (p<0.05) and a 21% decrease compared to subgroup 2 (p<0.05). Similarly, the hippocampus exhibited a 42.6% decrease in neuroglobin content compared to subgroup 1 (p<0.05) and a 28% decrease compared to subgroup 2 (p<0.05). Conclusion. Thus, the most pronounced disorders of the prooxidant-oxidant balance decreased neuroglobin were observed during a 1-day total cerebral ischemia. Keywords: neuroglobin, ischemia, pyramidal neurons, hippocampus, parietal cortex