[Plasma lipid spectrum and survival in rats with heart failure varied by severity under the influence of neurohormonal modulators].

In rats with relatively mild chronic heart failure (CHF) there was an increase in plasma LDL levels. In turn, in severe CHF it was revealed a significant decrease in total cholesterol concentration due to LDL levels decline. ACE inhibitors (captopril, enalapril and lisinopril) and the most selective beta1-adrenoblockers (metoprolol, nebivolol) had not any significant influence on plasma lipids. Less selective and especially nonselective beta-adrenoblockers pindolol and propranolol brought up the atherogenic potential of plasma because of HDL levels reduction in mild CHF whereas in case of severe model--due to the trends toward decrease in HDL concentration and toward increase in LDL levels. Lipophilic ACE-inhibitors and beta-adrenoblockers without intrinsic sympathomimetic activity improved survival in rats with mild CHF to the equal extent. On the contrary in severe CHF beta-adrenoblockers, especially non-selective, had an advantage over ACE inhibitors on the survival effect.

[Effect of angiotensin-converting enzyme inhibitors, beta-adrenoblockers, and their combinations on survival and plasma catecholamine levels in rats with chronic heart failure with induced exacerbations].

By using model of chronic heart failure (CHF) occurring with induced decompensations, it was shown that inhibitors of angiotensin-converting enzyme (ACE) and beta-adrenoblockers promoted to different degree the correction of hypercatecholaminemia and an increase of survival of rats. The most pronounced effect was characteristic of beta-adrenoblockers atenolol, propranolol, and carvedilol. The lower activity was demonstrated by other adrenoblockers that had no intrinsic sympathomimetic activity, as well as captopril. However, positive effect of these drugs on rat survival occurred regardless of their action on the sympathoadrenal system. The ACE inhibitors, particularly hydrophilic lysinopril, to the lesser degree than beta-adrenoblockers, prevented death of animals at the period of the CHF decompensation. The combined use of ACE inhibitors with beta-adrenoblockers, especially with carvedilol, promoted the maximally expressed decrease of the sympathoadrenal activity and an increase of the rat survival, including that at the CHF decompensation.

[Changes in lipid spectrum in rats with chronic heart failure of different severity on the background of angiotensin-converting enzyme inhibitors and beta-adrenoblockers].

The character of lipid spectrum changes in rats with experimental heart failure of non-ischemic genesis depended on its severity. In mild heart failure there was found an increase in the low density lipoprotein levels, whereas in the severe one--a decrease of total cholesterol levels at the expense of the low density lipoproteins. The ACE inhibitors produced no significant changes in the lipid spectrum. The effect of beta-adrenoblockers was determined by their selectivity for beta1-adrenoreceptors. The most selective drugs were distinguished by the metabolically neutral activity. On the contrary, nonselective beta-adrenoblockers increased the degree of plasma atherogeneity.

Peculiarities of heart rhythm variability in narcotized and immobilized wakeful rats during blockade of calcium channels.

In narcotized rats, verapamil and cinnarizine modified some heart rate variability (HRV) indices and heart rate (HR) indicating up-regulation of parasympathetic tone in contrast to nifedipine that elevated activity of sympathetic subdivision of ANS producing no influence on HR. In wakeful stressed rats, the time-domain and geometric analysis established that verapamil decreased HR and up-regulated sympathetic tone; nifedipine elevated sympathetic tone and produced no effect on HR, while cinnarizine enhanced parasympathetic tone without any effect on HR. Spectrum analysis of HRV revealed probable activation of some other neurohumoral mechanisms by the employed calcium blockers.

Heart rate variability in conscious and anesthetized rats under the action of angiotensin converting enzyme inhibitors.

We studied the effects of three various angiotensin converting enzyme inhibitors (enalapril, lisinopril and quinapril) on heart rhythm variability in anesthetized and immobilized rats. In all cases (except for quinapril in experiments on anesthetized animals), the preparations reduced the total rhythm variability and, according to spectrum analysis, increased activity of the parasympathetic autonomic nervous system to different degrees and decreased sympathetic tone. Quinapril and lisinopril produced the most pronounced influence on heart rhythm in anesthetized rats; enalapril was less potent in this respect. In immobilized animals, quinapril and enalapril showed the greatest activity and lisinopril the lowest. The more pronounced effect of quinapril both under anesthesia and during immobilization appears to be linked to the highest affinity of quinaprilat to circulatory and tissue compartments of the renin-angiotensin-aldosterone system.

Heart rate variability in kittens during early postnatal ontogeny.

Heart rate variability in awake kittens under resting conditions was studied during the following periods of postnatal ontogeny: newborn animals, 10-day-old animals (eye opening), 20-day-old animals (rise on the legs), and 30-day-old animals (control). Newborn animals were characterized by high activity of the sympathoadrenal system due to birth stress. The effect of stress factors increased in 10-day-old kittens, which was related to the start of functioning of distant receptors and delivery of new environmental information into the brain. The acquisition of upright posture and locomotion on the limbs were accompanied by activation of the vagus nerve in kittens. Significant changes in temporal, geometric, and spectral characteristics illustrate an increase in adaptability of the organism and possibility for independent living (particularly, by the 30th day of life).

Lipid composition in rats with nonischemic chronic heart failure.

The initial stages of nonischemic chronic heart failure in rats (model of oleothorax) were accompanied by the development of dyslipidemia. This state was characterized by an increase in total cholesterol concentration (due to the fraction of low-density lipoproteins) and atherogenicity index. The concentrations of plasma total cholesterol and low-density lipoproteins were shown to decrease in animals with severe course of nonischemic chronic heart failure. These changes were accompanied by a decrease in the atherogenicity index. Intragastric administration of cholesterol had little effect on the lipid composition of blood plasma in rats, irrespective of the severity of heart failure.

[Neurohumoral mechanisms of the rat heart adaptation to overload].

The present study confirms involvement of the sympathicoadrenal system in adaptation of heart to overload. Besides, at formation of chronic heart failure (CHF) there have been revealed a rise of the histamine and serotonin levels in blood plasma and myocardium as well as glucocorticoid hyperactivation.

[The levels of thyroid hormones in hemorrhagic stroke].

Radioimmunoassay using was used to study the blood concentrations of thyroid hormones (thyroid-stimulating hormone (TSH), T3, and T4) in patients with hemorrhagic stroke as intracerebral hematoma. The authors analyzed two patient groups: 1) those operated on for intracerebral hematoma removal; 2) those receiving medical treatment. Surgical intervention resulted in local fibrinolysis of a hematoma remnant. The level of thyroid hormones was studied over time from the 1st day to the 28th day of therapy. Each group was then divided into 2 subgroups: survivors and dead patients. Mortality group was 77.2% in the medical treatment group and 17.2% in the surgical treatment group. The performed studies established elevated concentrations in cases of good outcome of stroke. All the patients were found to have low T3 concentrations that were more pronounced in patients with a poor outcome. The level of T4 did not differ from the control values in patients with good results. Hematoma removal contributed to an increase in the concentrations of TSH and triiodothyronine.

Effect of beta-adrenoblockers on heart rate variability in awake and narcotized rats.

In narcotized rats, beta-adrenoceptor blockers changed all parameters of heart rate variability indicating up-regulation of parasympathetic activity and down-regulation of the sympathetic one. In immobilized awake rats, the temporal and geometrical parameters varied similarly, while spectral analysis indicated possible activation of other neurohumoral mechanisms against the background of beta-blocker treatment.

Survival of rats with experimental chronic heart failure depending on pharmacodynamic and pharmacokinetic parameters of angiotensin-converting enzyme inhibitors and beta-adrenoceptor blockers.

Lipophilic inhibitors of angiotensin-converting enzyme increased 6-month survival and/or lifetime of rats with experimental chronic heart failure. These drugs had no effect on the mortality rate of animals with acute decompensation of the disease. beta-Adrenoceptor blockers without intrinsic sympathomimetic activity not only prolonged 6-month survival and lifetime, but also decreased the mortality rate of rats with decompensation of chronic heart failure.

[Morphometric characteristics of rat viscero- and somatosensory neurocytes of the caudal ganglia in the vagus nerve]. / Morfometricheskaia kharakteristika vistsero- i somatosensornykh neirotsitov kaudal'nogo uzla bluzhdaiushchego nerva krysy.

In experiments performed in 63 adult albino male rats, the participation of afferent neurons of caudal vagal ganglion in the innervation of different organs was investigated. Horseradish peroxidase and conjugate of horseradish peroxidase with wheat germ agglutinin were used as the tracers. Metric parameters (diameter of an equivalent circle) and shape parameters (circular factor of the form) of marked neurocytes were studied using computer videoanalysis method. The dependence of neuronal cell body dimensions on the distance to the innervated target organ was established. The exclusion was represented by the neurocytes, innervating the root of the tongue, which are larger than those projecting to the pancreas. The reason for these discrepancies seems to be associated with the differences of viscero- and somatosensory relations.

[Populations of afferent neurons in the sensory ganglia detected using lectin from Laburnum anagyroides]. / Populiatsii afferentnykh neironov v chuvstvitel'nykh uzlakh, vyiavlennye s ispol'zovaniem lektina bobovnika anagirolistnogo.

The purpose of the present research was the study of afferent neuron subpopulations in vagal caudal ganglia and trigeminal ganglion of adult albino rats using a conjugate of fucose-specific Laburnum anagyroides lectin (LAL) with peroxidase. Histochemical preparations obtained were examined using computer videoanalyzer with the determination of dimensions of afferent neurons and integral optical density (IOD) of their cytoplasm. In the ganglia studied LAL was found to bind to the majority (more than 98%) of neurons. Reaction product was demonstrated in the perikaryon either as discrete granules (Nissl body-type), or as a uniform precipitate. Nucleoplasm in most of neurons remained lightly stained. Determination of IOD of neuronal cytoplasm in various ganglia demonstrated significant differences in degree of LAL accumulation. Analysis of interrelation between neuronal size and IOD permitted to establish non-linear correlation of metric and optical parameters and to detect subpopulations of cells in the sensory ganglia, which were stained with LAL most intensely. Functional specialization of these cells remains to be determined. Thus, a combined application of lectin-histochemical method with a computer videoanalysis of morphological slides enabled the identification neuronal populations and subpopulations in rat afferent ganglia, which are not demonstrated with the standard histological methods.

Age-dependent changes of electrophysiologic characteristics of the stellate ganglion conducting pathways in kittens.

The conducting pathways of the cat stellate ganglia were examined in newborn, 10- and 20-day-old kittens by recording the evoked responses in the branches of the ganglion following electrical stimulation of its other branches. In the course of postnatal ontogenesis, the average conduction velocity of excitation and the average amplitude of the responses was increased. In newborn and 10-day-old kittens, all fibers on their conduction velocities belong to C-fibers. In 20-day-old kittens, Adelta- and B-fibers also appeared. In this age-group, two subgroups among fibers of the C group were determined according to their conduction velocity of excitation. From 10 days of age, the axon reflex was recorded in the anastomosis and the inferior cardiac nerve following stimulation of the cranial and caudal branches of the subclavian loop. All branches of the stellate ganglia of 20-day-old kittens contain both continuous and synaptically switched fibers.

[The electrophysiological properties of the conduction pathways of the stellate ganglion in the cat in postnatal ontogeny]. / Elektrofiziologicheskie svoistva provodiashchikh putei zvezdchatogo gangliia koshki v postnatal'nom ontogeneze.

In new-born, 10-, and 20-day-old kittens and in adult cats, the stellate ganglia branches contained both continuous and synaptically interrupted fibres. In the course of postnatal ontogenesis, the average conduction velocity of excitation and average amplitude of the responses increased. In new-born and 10-day old kittens, these are C-fibres. Apart from the latter, A delta and B fibres appeared in 20-day old kittens. In adult cats, two subgroups of all types of the fibres appeared. Since the 10-day age, synaptically interrupted responses have been recorded in anastomoses and inferior cardiac nerve following stimulation of cranial and caudal branches of the subclavian loop, the responses being conducted in both directions in adult cats.

[Asymmetry of the neuronal organization of the cat stellate (cervicothoracic) ganglion in the postnatal period of ontogenesis]. / Asimmetriia neironnoi organizatsii zvezdchatogo (sheino-grudnogo) uzla koshki v postnatal'nom periode ontogeneza.

By direct and indirect morphometry the cell density maximal diameter and area of section of neurocytes in the zones of the emergence of the basic nerves and in the centre of the stellate ganglion were determined in kittens of various ages and adult cat. There is an increase of the maximal diameter, average area of section of neurons (16.98 +/- 0.07 mm and 132.2 +/- 0.9 mm2 in newborn, 21.7 +/- 0.72 mm and 31.4 +/- 2.6 mm2 in 10-days, 6.69 +/- 0.5 mm and 355 +/- 2.4 mm2 in 20-days kitten, 4.86 +/- 0.6 mm and 634 +/- 36 mm2 in adult cat and reduction of cell density of ganglionic neurons in postnatal ontogenesis. In newborn kitten, kittens of 10- and 20-days of age and adult cat larger neurons were located in the cranial part of the ganglion. In 10 and 20 days kittens and adult cats an asymmetry between right and left stellate ganglia in the maximal diameter and average area of section of neurons was revealed. In adult cat the asymmetry in the cell density was also found between both ganglia.

[Efferent sympathetic preganglionic and afferent spinal transit pathways of the cat stellate ganglion]. / Efferentnye simpaticheskie preganglionarnye i afferentnye spinal'nye tranzitornye puti zvezdchatogo gangliia koshki.

Using a technique of retrograde axonal transport of horseradish peroxidase, labeled neurons were detected in the intermedialateral nucleus (pars principalis and pars funicularis), intercalatous spinal nucleus, and in the ventral horns of the spinal cord in cats. Afferent spinal transit pathways pass in all the above branches as well as the vertebral nerve. Bodies of the labeled neurons with branches passing in the vertebral nerve are located in the T2-T7 spinal ganglia, whereas those with branches passing in other nerves--are located in the C8-T8.