Indicators of Bioelectrical Activity of the Rat Heart After Prenatal Hypoxia and Pharmacological Correction

Abstract

Background. Posthypoxic cardiopathy is one of the risk factors for the development of cardiovascular pathology (rhythm disturbances, vascular dystonia, etc.) in subsequent age periods and requires the development of treatment approaches. Objective. to evaluate the cardioprotective effect of modulators of the NO system by the effect on the ECG of rats after intrauterine hypoxia. Methods. Modeling of prenatal hypoxia (PH) by daily intraperitoneal administration of sodium nitrite solution to pregnant female white rats weighing 220–240 g, aged 4.5 months, from the 16th to the 21st day of pregnancy at a dose of 50 mg/kg. The offspring were administered daily from the 1st to the 30th day of life – tiazotic acid (morpholinium 3-methyl-1,2,4-triazolyl-5-thioacetic acid), 50 mg/kg, angiolin ([S]-2,6-diaminohexane acid 3-methyl-1,2,4-triazolyl-5-thioacecate), 50 mg/kg, L-arginine, 200 mg/kg, meldonium (2-(2-carboxyethyl)-1,1,1-trimethylhydrazinium), 100 mg/kg. Аnd then after 2 months of life, an ECG was recorded using the ECG TUNNEL system (without anesthesia). Results. Postponed PG leads to a decrease in heart rate and significant dominance of parasympathetic innervation in regulation of electrical activity of the heart, which can be caused by sinus blockade and may be a reflection of parasympathetic regulation of the heart instead of sympathetic control of electrical activity in the norm. The effectiveness of drugs can be presented in descending order: angiolin > tiazotic acid > meldonium. Angiolin proved to be more effective than tiazotic acidin normalizing the electrical activity of the heart and restoring the neurogenic regulation of the automatism of the function of the sinus node. Сonclusions. The prospects of further study of modulators of the NO system with different mechanisms of action as means of cardioprotection of posthypoxic disorders of the cardiovascular system in newborns are experimentally substantiated.

Altered Blood Molecular Markers of Cardiovascular Function in Rats after Intrauterine Hypoxia and Drug Therapy

“…In our previous study, it was found that the use of this model of PH leads to a decrease in myocardial contractility and sinus node dysfunction. Cells with signs of apoptosis and dystrophy are detected in the contractile myocardium and conduction system with a certain correlation between the severity of morphological changes and bioelectric rhythm and conduction disorders [31]. The basis of pathological processes in the action of sodium nitrite is hypoxia of mixed genesis, hemic hypoxia due to the formation of methemoglobin, which is combined with tissue hypoxia due to dissociation of oxidation and phosphorylation processes.…”

“…Ivanitskaya [33]. Also, a number of works have obtained results indicating that exposure to sodium nitrite in the prenatal period can lead to posthypoxic heart damage, ECG [31] myocardial ultrastructure (increase in the proportion of irreversibly damaged mitochondria in the CMC of the intramural zone of the right ventricle) [34], and contractile changes [35,36]. In both newborn and adult animals, our model allows for the evaluation of physiological development in offspring and the effectiveness of experimental cardioprotective therapy after prenatal hypoxia (PH).…”