Vol 144, No 6 (2013)

The study was performed on the offspring, obtained from 8 female Wistar rats, which were administered parachlorophenylalanine on day 16 of gestation, to deplete the endogenous serotonin in their offspring. Dorsal and ventral subnuclei of the parabrachial complex lateral part were studied in rats on postnatal days 10 and 14 days (5–6 animals for each time point) using histological, immunocytochemical and morphometric methods. It was shown that serotonin deficiency changed the structure of the subnuclei. In the ventral subnucleus, the population of large multipolar neurons was more sensitive to low levels of serotonin. In experimental animals, the size of neuron cell bodies was reduced 1.6 times in comparison with the control, while cell numbers in the population remained practically unchanged. Morphological characteristics of smaller neurons corresponded to those in the control group, but their numbers were reduced, which probably can explain some rarefaction of neurons in the nucleus. In dorsal subnucleus of the experimental animals, the neurons of both populations had more pronounced changes. Sizes of the cell bodies in both large and small neurons was significantly decreased 2.0 and 1.8 times, respectively; the volume of their cytoplasm was significantly reduced, compared to that in control animals, while the number of cells in both populations remained practically unchanged. The reaction demonstrating glial fibrillary acidic protein has shown that the astrocytic glial population was increased in both subnuclei in the experimental animals in the early postnatal period.

The aim of this investigation was to demonstrate the regulatory elements in the skin epithelium of Enteropneusta which are supposed to be related to the chordate ancestors. Using electron microscopy, it was found that in the skin epithelium of a representative of enteropneusts Saccoglossus mereschkowskii, the basal parts of some epitheliocytes took part in formation of a nerve layer. These cells were considered as receptor ciliated cells. The granular epithelial cells were shown to release secretion according to both exocrine and endocrine mechanism; these cells were characterized as endocrine-like regulatory cells. Fine granular cells possibly represent special receptor-endocrine-like cell type. The immunocytochemical detection of FMRFamid neuropeptide localization in histological sections confirmed the electron microscopic data on the presence of receptor and endocrine-like cells in the epithelium. It is suggested that the skin epithelium of Enteropneusta contains a peculiar neuro-endocrine regulatory system that is represented by receptor cells, receptorendocrine-like cells of an open type and nerve elements of the nerve layer.

The effect of chronic exposure to general vibration on the state of hemomicrocirculatory bed in the organs of rat masticatory apparatus and the efficacy of antihypoxants and adaptogens for its pharmacological prophylaxis was studied. The experiments were performed in 210 albino male rats aged 8 to 30 weeks. The intact rats served as control. Transcapillary injections with 1% collargol solution, histological, electron microscopic and morphometric methods were used. It was found that chronic exposure to general vibration induced a hemodynamic disturbances at the level of hemomicrocirculatory bed vessels in the organs of masticatory apparatus with subsequent hypoxia. Electron microscopic study revealed the damage of the cellular ultrastructure in the endotheliocytes of blood vessels of the hemomicrocirculatory bed. Antihypoxants, adaptogens and their combinations demonstrated a pronounced protective effect

Using the quantitative methods, the remodeling of the cytoarchitectonics of the morpho-functional zones in the grouped lymphoid nodules (GLN) or Peyer’s patches and in the mesenteric lymph nodes (MLN) were studied in 30 rats after 30-day-long exposure to hypokinesia and during the period of rehabilitation (30 days after hypokinesia discontinuation). It was found that following the hypokinesia the germinal centers in lymphoid nodules in GLN retained the lymphocytopoiesis, while in the internodular zone the proportion of immature cells was increased and plasma cells appeared. In the similar structural zones of MLN, the complete suppression of lymphocytopoiesis and T-cell maturation was noted. During the rehabilitation period, the cytoarchitectonic indexes recovery was more pronounced in GLN than in MLN. However, the quantitative parameters of their cellular composition did not reach the values found in the group of intact of animals.

One of the causes of drug hepatopathy is hepatocyte apoptosis, the mechanisms of which are still unclear. The experiments were performed in 24 Wistar rats to study the role of hepatoprotectors in the regulation of hepatocyte apoptosis in liver damage induced by administration of antituberculosis drugs (ATD). The level of apoptosis (TUNEL) was evaluated, and the expression of apoptosis-associated molecules was detected by immunohistochemistry and Western blotting. It was shown that a signaling cascade induced by ATD involved the activation of cell surface receptors (CD95) and caspase-8, i.e. apoptosis was mediated by extrinsic pathway. In addition, ATD induced p53 oncosuppressor synthesis with further activation of caspase-3 effector. Runihol administration during ATD treatment administration improved the condition of the liver, despite some apoptosis stimulating effect, mediated by an intrinsic pathway. It was found that runihol blocked both FAS- and p53-dependent pathways. Ademethionine during drug intoxication acts as a hepatoprotector, blocking extrinsic and p53-dependent pathways.

A protocol of immunocytochemical demonstration of choline acetyltransferase (ChAT), a key enzyme of acetylcholine synthesis, in paraffin sections of the brain of some laboratory animals, is presented. The method is simple, gives fairly reproducible results and allows for demonstration of ChAT in neurons, nerve fibers, and terminals in preparations of at least three species of laboratory animals including rat, rabbit, and cat. Different kinds of fixation (10% formalin, 4% paraformaldehyde, or zinc-ethanol-formaldehyde) were found suitable for immunocytochemical visualization of ChAT, however, optimal results were obtained with the application of zinc-ethanol-formaldehyde