Vol 129, No 1 (2006)

This review summarizes the information on the interrelations between intracellular localization of NO-synthases (NOS) and their regulatory functions within different compartments of a cardiomyocyte in the light of general conception of Barouch et al. (2002) on the intracellular «spatial compartmentalization» of NOS isoforms. Participation of NO in cardiomyocyte function control is based on complex spatial compartmentalization of NOS isoforms: neuronal (NOS1), inducible (NOS2) and endothelial (NOS3), which possess unequal activities resulting in hundredfold differences in the concentrations of gas produced. Regulatory role of constititive Ca-dependent NOS1 and NOS3 is associated with production of low NO concentrations, which cause a decline in cardiomyocyte contractility and a reduction in heart rate. Conversely, Ca-independent inducible NOS2 appears only in the damaged myocardium with a compromised contractile function. NOS2 produces high unregulated NO concentrations, which are connected with the generation of peroxynitrites and NO cytotoxic action. NOS3 is associated with the membranes of cardiomyocyte caveoli and T-tubules, while NOS1 is localized on the sarcoplasmic reticulum membranes. NOS isoform compartmentalization promotes regulation of different circuits in NO-signaling pathways in myocardium, and this principle is a key for understanding of contradictions existing in NO biology in the heart. Changes in NOS subcellular compartmentalization lead to the increased NO synthesis, reduction of the specificity of its effects, disruption of calcium cycle mechanisms, electromechanical uncoupling and myocardial contractility failure. The mechanisms of selective effects of different NO-ergic regulatory pathways on the activity of five major targets in pacemaker and working cardiomyocytes, are discussed.

The aim of this work was to study the primary structural modular organization of neurons in dorsal thalamic nuclei (ventral anterior, ventral lateral, anterior medial, anterior ventral, anterior dorsal, medial, nucleus reticularis) and motor cortex (areas 4 and 6) in man using the methods of Nissl, Kluver-Barrera and Golgi silver nitrate impregnation. It was shown that in both dorsal thalamic nuclei and motor cortex neurons had regular organization - they were forming small groups or short chains and meet specific criteria. These neuronal associations, formed single structural units, that were called primary structural moduli. Comparison of primary structural moduli found in dorsal thalamic nuclei and motor cortex has demonstrated the identity of their organizational principle. The differences were only in the cells, that formed primary structural moduli. Thus, in human dorsal thalamic nuclei and motor cortex two principles of neuronal organization into primary structural moduli were detected - group and chain.

Epitheliocytes of choroid plexus vili of lateral (glomus), III and IV (lateral portion) brain ventricles were studied in humans aged 22 to 89 years. Height, width and profile area of the cells, as well as nuclear and cytoplasmic profile areas were measured and nucleo-cytoplasmic indexes were calculated. The shape of epitheliocytes was found to be variable and to be associated with their location on the vilus surface. Epitheliocyte height, cytoplasmic and cell profile area were maximal in the choroid plexus of lateral ventricle, nuclear profile area and epitheliocyte nucleo-cytoplasmic index - in the choroid plexus of IV ventricle. These differences in epitheliocyte parameters are thought to be associated with the peculiarities of their functioning. In the process of aging, the dimensions of epitheliocytes and their nuclei were found to decrease, while the nucleo-cytoplasmic index was reduced, reflecting the development of adaptational remodeling.

In experiments on rats, changes of the ultrastructure of myocardial histo-hematic barriers in the right atrium during short-term and prolonged heat stress were studied. Short-term heat exposure (40°C, 30 and 60 min) increased the rectal temperature by 3.0-3.5°C. Immediately after heat exposure and 24 and 48 h following the exposure, the destructive and compensatory adaptive alterations in the microcirculatory bed were detected, accompanied by an edema of the pericapillary space and the changes in the size of mitochondria under the cardiomyocyte sarcolemma. Prolonged heating (40°C, 4 h daily for led to an increase in the rectal temperature by 0.4-1.6°C. Changes in the microcirculatory bed had both dystrophic and compensatory adaptive nature. Erythrocyte and thrombocyte sludge and erythrocyte lysis were found in the lumen of microvessels. The number of endocytotic vesicles in endotheliocytes was variable; endotheliocyte nuclei had increased electron density and irregular outline. Myelin-like structures and apoptotic bodies were found in the pericapillary spaces. Under the cardiomyocyte sarcolemma the accumulation of mitochondria and sarcoplasmic vacuolization were noted. Comparison of short- and long-term effects of heat on histohematic barriers in the right atrium shows more significant changes after prolonged heat stress.

The aim of the study was a comparative analysis of the proliferative activity of thymocytes and peripheral blood lymphocytes in the offspring of female rats with chronic liver pathology of various genesis. In adult female Wistar rats toxic and autoimmune forms of liver lesions were modeled. The offspring of these experimental animals was studied at different time points of postnatal ontogenesis. Proliferative activity of thymocytes and lymphocytes was estimated by counting the proportion of cells with multiple nucleolar organizing regions (AgNORs) and using the cytofluorometric method with acridine orange. In the offspring of experimental animals, the depression of proliferative activity of thymocytes as well as the increase of the proliferative activity of peripheral blood lymphocytes were found at all the time points studied. This was indicated by a change in a relative number of AgNORs-activated cells and a decrease of nucleic acid content in cortical thymocytes.

The aim of this study was to determine the changes in the pancreas structure after acute and chronic exposure of organism to gravitational overloads (GO). The experiments were conducted in 36 outbred albino male rats, 12 rats formed the control group. GO effect was modeled using the centrifuge; the value of the overload thus created amounted to 4,0-6,0 gravitational units. Pancreas structure was studied using histological, electron microscopic and morphometric methods. It was found that after acute exposure to GO, mainly the reactive changes were demonstrated all the pancreatic structures studied: acinocytes, endocrinocytes, blood vessels and nervous apparatus. Chronic exposure to GO resulted in both reactive modifications, similar to those described after an acute exposure, and various compensatory-adaptive and destructive changes.

The dynamics of the processes of proliferation and apoptosis in the epithelium of the bulbourethral glands in men aged 17-90 years was studied using monoclonal antibodies against PCNA and p53. Higher levels of cell reproduction and cell death were noted in the glandular duct epithelium as compared to those in secretory portions. Age-related increase in apoptosis which correlated with the activation of the glandular cell proliferation was shown. In old men, apoptosis in the bulbourethral glands was accompanied by the tendency to reduced cell proliferation. The correlation between the processes of cell reproduction and cell death in the epithelium of the bulbourethral glands, as well as their dependence on blood androgen levels, are discussed.

The experimental study was performed to evaluate the biological effects of parenteral injection of cerebrospinal fluid (SCF) on the uterus, uterine tubes and the ovary of piglets aged 60 days. Lactating cows aged 4-6 years after first calving were taken as SCF donors, since their SCF contained maximal spectrum of biologically active substances. For injection the whole SCF, SCF after passage through bacterial filters and SCF supernatant were used. The effect of SCF was assessed using histological and histochemical (succinate- and lactate dehydrogenases demonstration) methods. It was found that SCF preparations studied had differential effect on oxidative-reduction processes in the tissues of reproductive system organs of immature pigs, that is associated with the broad spectrum of biologically active substances in mammalian SCF.

In reply to the article of an opponent, the author presents new personally obtained data on the similarity of some brain neurons possessing asynaptic dendrites and innervating the perivascular space, pia mater (from inside), or having the direct contact with the ventricular cerebrospinal fluid, to the local autonomic Dogiel's II type neurons of the viscera. Author also demonstrates personal electron micrographs showing the terminals of asynaptic dendrites of brain neurons which are not different in any aspect of their ultrastructure from the terminals of visceral receptors. The facts are presented, that, in author's opinion, refute the opponent's conceptions on the impossibility of the various receptor functions of the cilia in general, and in ciliated neurons, in particular, on the development of sensory neurons from the neural crest only, and on the impossibility of the sensory innervation of the brain tissues, in principle.