Vol 55, No 3 (2019)

The review addresses the mechanisms of adaptation of cardiomyocytes to hypoxia and ischemia and analyzes the signaling mechanisms responsible for expression of metabolic genes and the formation of tolerance to hypoxia and ischemia with a special focus on the role of HIF-1α, succinate, and ATP-dependent K⁺-channels (K_ATP-channels) in the regulation of adaptive responses of cardiomyocytes during myocardial ischemia.

The directional effect on albumin of the molecules which modulate its binding and/or esterase activity could allow stoichiometric and/or catalytic detoxification of organophosphates in the bloodstream. In this study, the effect of polyphenols on binding and catalytic activity of human (HSA) and rat (RSA) serum albumins has been investigated by molecular modeling on the examples of trans-resveratrol and paraoxon. Molecular docking of the paraoxon molecule into the Sudlow II site of HSA and RSA was followed by a calculation of conformational changes and free energies of the albumin-paraoxon complex formation using molecular dynamics simulation. The same calculation was carried out in the presence of a trans-resveratrol molecule in the Sudlow I site. It has been shown that the effect of resveratrol only consists in decreasing pseudo-esterase activity of RSA towards paraoxon.

This study deals with the dynamics of lactate dehydrogenase (LDG) activity in brain structures during early postnatal ontogenesis (days 17 and 30) and the reproductive period (day 90) of white rats exposed to hypoxia in the fetal period of prenatal ontogenesis (days 18-20). It was established that in rats that underwent prenatal hypoxia in the fetal period the level of LDG activity did not reach its control values with age during postnatal ontogenesis. In most cases, hypoxia led to increase LDG activity in the brain structures.

Activities of the somatomotor, cardiovascular and respiratory systems were investigated in conditions of impaired cholinergic regulation in rat pups aged 1 and 16 days. Acetylcholinesterase (AChE) inhibition by physostigmine (eserine), which leads to activate cholinoreactive structures, is accompanied by a unidirectional impairment of the cardiac sinus rhythm in newborn and, to a lesser extent, 16-day-old rats. Activation of cholinoreactive structures decreases the rate and regularity of breathing and also alters the pattern and parameters of motor activity. Physostigmine injection potentiates motor activity in 1-day-old and depresses it in 16-day-old rats. The blockade of muscarinic cholinoreceptors in rats of both age groups largely affects functional activity of the cardiovascular system, preventing severe cardiac arrhythmias caused by injection of the AChE inhibitor. It was shown that the formation of the definitive level of cholinergic regulation, including the maturation of the mechanisms underlying reciprocal interactions within the cholinergic system itself, is completed in the early period of rat postnatal ontogenesis. Age-related differences in responses of the somatomotor, cardiovascular and respiratory systems to changes in the level of activation of cholinoreactive structures are associated with these processes.

The endogenous gaseous transmitters (GTs) —nitrogen oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H₂S)—make up a special neuromodulatory system which mediates the development, maturation and plastic modification of nervous centers. We addressed immunolocalization of the key enzymes of GT synthesis, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), heme oxygenase-2 (HO-2) and constitutive NO synthase (nNOS), at different ontogenetic stages of the human fetal retina. CBS, CSE and HO-2 were found to be expressed in photoreceptor, bipolar and amacrine neurons, the number of which increases in the first and decreases in the third trimesters of gestation. The number of nNOS-immunopositive amacrine and ganglion neurons demonstrates inverse dynamics with maximal values in the third trimester. Uneven distribution patterns of the marker enzymes are discussed in the light of the modulatory function of GTs in neurogenesis of the human retina and their involvement in cytoprotective mechanisms.

On page 158. In the title of the article Lysozime should read Lysozyme.