The content of ATP Synthase in Cerebral Ischemia of Varying Severity Comparative Analysis

Karnyushko Olga A.,Bon Elizaveta I.,Lychkovskaya Maria A,Zimatkin Sergey M,Maksimovich Natalia E.

doi:10.31579/2766-2314/064

Abstract

Objective. Evaluation of changes in the content of ATP synthase in the parietal cortex and hippocampus of the brain of rats with ischemia of varying severity in a comparative aspect. Methods. The experiments were performed on 88 male outbred white rats weighing 260 ± 20 g. Brain ischemia was modeled under conditions of intravenous thiopental anesthesia (40-50 mg / kg). Total cerebral ischemia was modeled by decapitation of animals. The brain sampling was carried out 1 hour and 24 hours after decapitation - to study tissue respiration of mitochondria, as well as 1 hour later to determine the content of ATP synthase. Subtotal cerebral ischemia was modeled by simultaneous ligation of both common carotid arteries. The material was taken after 1 hour to determine the content of ATP synthase. Stepwise subtotal cerebral ischemia was performed by sequential ligation of both common carotid arteries with an interval of 7 days. The sampling was carried out 1 hour after ligation of the second common carotid artery in each of the subgroups. Partial cerebral ischemia was modeled by ligation of one common carotid artery on the right. The sampling was carried out 1 hour after the operation. Determination of the content of ATP synthase was carried out by immunohistochemical method using monoclonal antibodies. For this purpose, after decapitation, the brain was quickly removed from the rats, pieces of the cerebral cortex were fixed in zinc-ethanol-formaldehyde at + 4 ° C (overnight), then embeddedвinвparaffin. Results. In the group of stepwise subtotal cerebral ischemia, the smallest decrease in the content of ATP synthase was observed in the 1st subgroup with an interval between dressings of 7 days, while the greatest decrease in the content of the enzyme was noted in the 3rd subgroup with the minimum interval between the dressings of the common carotid artery (1 day). Modeling of more severe types of ischemic damage led to pronounced morphological changes in neurons in the parietal cortex and hippocampus of the rat brain - a decrease in their size, deformation of the perikarya, an increase in the degree of neuronal chromatophilia with their simultaneous wrinkling and subsequent death. These disorders were most pronounced in the 3rd subgroup of stepwise subtotal cerebral ischemia with the shortest interval between dressings, which was 1 day, and in the group of total cerebral ischemia. Conclusion. Thus, the most pronounced decrease in the content of ATP synthase was observed in the groups of total cerebral ischemia, subtotal cerebral ischemia and in the 3rd subgroup of stepwise subtotal cerebral ischemia, with a minimal time interval between the ligation of the common carotid artery. In stepwise subtotal cerebral ischemia with an interval between ligation of the common carotid artery of 7 days, the suppression of the ATP synthase content was not so significant.

Highlights

In cerebral ischemia (CI), a chain of pathogenetic disorders develops in its structures, among which one of the leading is energy deficiency, which leads to the development of cellular pathology [1, 2]
In the group of stepwise subtotal cerebral ischemia, the smallest decrease in the content of ATP synthase was observed in the 1st subgroup with an interval between dressings of 7 days, while the greatest decrease in the content of the enzyme was noted in the 3rd subgroup with the minimum interval between the dressings of the common carotid artery (1 day)
Modeling of more severe types of ischemic damage led to pronounced morphological changes in neurons in the parietal cortex and hippocampus of the rat brain - a decrease in their size, deformation of the perikarya, an increase in the degree of neuronal chromatophilia with their simultaneous wrinkling and subsequent death. These disorders were most pronounced in the 3rd subgroup of stepwise subtotal cerebral ischemia with the shortest interval between dressings, which was 1 day, and in the group of total cerebral ischemia

Summary

Introduction

In cerebral ischemia (CI), a chain of pathogenetic disorders develops in its structures, among which one of the leading is energy deficiency, which leads to the development of cellular pathology [1, 2]. A number of molecular markers of the energy activity of mitochondria are known, among which one of the main markers is ATP synthase - an integral protein of the inner mitochondrial membrane that carries out the reaction of ATP formation from ADP [7, 8]. Mitochondrial ATP synthase plays an important role in the differentiation of stem cells, promotes the formation of mitochondrial cristae by dimerization and specific regulation [9, 10, 11]. The enzyme belongs to the alpha / beta ATP synthase family. Consists of two structural domains (F1 - extramembrane catalyst and F0 - membrane proton channel), connected by a central rod consisting of γ, δ and ε subunits [12, 13, 14, 15], and together with the oligomer of the membrane subunit representing the rotary domain of the enzyme [1,4,7,16,17]

Methods

Results

Discussion

Conclusion