I.V. Zadnipryany, T.P. Sataieva

Perinatal hypoxia and its possible correction

The problem of hypoxia for many years is very relevant and attracts the attention of physiologists and clinicians in terms of the mechanisms of various pathological conditions. Hypoxia is characterized by inadequate oxygen delivery to the myocardium with a resulting imbalance between oxygen demand and energy supply. Several adaptive mechanisms occur to preserve myocardial survival during hypoxia. These include both short- and long-term mechanisms, which serve to achieve a new balance between myocardial oxygen demand and energy production. Short-term adaptation includes downregulation of myocardial function along with upregulation of energy production via anaerobic glycolysis following an increase in glucose uptake and glycogen breakdown. Long-term adaptation includes genetic reprogramming of key glycolytic enzymes. Thus, the initial decline in high-energy phosphates following hypoxia is accompanied by a decrease in myocardial contractility and myocardial energy requirements are subsequently met by ATP supplied from anaerobic glycolysis. Thus, a downregulation in cardiac function and/or enhanced energy production via anaerobic glycolysis are the major mechanisms promoting myocardial survival during hypoxia. In contrast to the aforementioned metabolic changes occurring in adult myocardium, the effects of chronic hypoxia on neonatal myocardial metabolism remain undefined. Effects of antenatal hypoxia in the infants depend on the severity of exposure, individual tolerance, and the age of fetus. In the literature, there is a large amount of data on the effect of antenatal hypoxia during last trimester of pregnancy on the development of the newborn. There is a reduction of oxygen supply to parts of the body below what is required for adequate perfusion. However, there is no much data about the effect of hypoxia on the embryo stage during the first cleavage, the formation of the blastula, gastrula, primary organ systems and the subsequent development of the organism in the postnatal period. One possible way to diminish the negative effects of hypoxia is to apply the peptide complexes. Asphyxia of the fetus and newborn are accompanied by hemodynamic disorders. Revealed by light microscopy data suggest that significant changes happen the heart muscle and in the blood vessels of all calibers. For example, a study of the effect of antenatal hypoxia in sheep showed an increase in the diameter of the capillaries and reducing the density and length of the right ventricle compared with the left. In addition, antenatal hypoxia may delay the development of the myocardium. Available descriptions of ischemic and hypoxic damage to the heart during antenatal hypoxia indicate that particularly sensitive to oxygen deficiency are contractile cardiomyocytes of subendocardial layer and papillary muscles. It is this the location of the cardiomyocytes related to the peripheral regions of the conduction system of the heart. Progressive left ventricular dilatation and inadequate hypertrophy of the surviving myocardium were confirmed by echocardiography. Plaque rupture with subsequent exposure of the basement membrane results in platelet aggregation, thrombus formation, fibrin accumulation, hemorrhage into the plaque, and varying degrees of vasospasm. This can result in partial or complete occlusion of the vessel and subsequent myocardial ischemia.

At present researchers think about application of a number of regulatory peptides and their constellation to correct the consequences of shock states, including antenatal hypoxia. Peptides are short chains of amino acid monomers linked by peptide (amide) bonds, the covalent chemical bonds formed when the carboxyl group of one amino acid reacts with the amino group of another. Peptides are distinguished from proteins on the basis of size, and as a benchmark can be understood to contain approximately 50 amino acids or less. The shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, tetrapeptides, etc. A polypeptide is a long, continuous, and unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological oligomers and polymers, alongside nucleic acids, oligo- and polysaccharides, etc. A new step in the treatment of stable angina pectoris, myocardial infarction is a cytoprotective therapy aimed at optimizing metabolism in cardiomyocytes damaged by ischemia. Cardioprotective effect is achieved due to sufficient energy supply, which helps to maintain normal cardiac contractility. Research and application of new drugs in cardiology practice that can enhance the effectiveness of treatment of patients with myocardial infarction are highly relevant. Promising in this aspect is the Liposomal drug Lipin - this drug is of natural origin, which is a freeze-dried egg phosphatidylcholine. The choice of the drug due to the fact that lipin is related to structural antioxidants, and purposefully exercises their protective effect on cell membranes due to its ability for its ability to be integrated into plasma membranes.