Dynamics of Organization of the Microcirculatory Bed and Mast Cells of the Uterus in Rats at Different Times of the Day.

Structural organization of the microcirculatory bed and mast cells in the uterus of mature female Wistar rats (n=60) were examined every 2 h over 24 h. During night hours, many vessels characterized by intensive reaction to NADPH-diaphorase and endothelial NO synthase were detected in the endometrium, and the density of these vessels and mast cells was quite high. During the day and evening hours, the capillaries with high levels of enzymes involved in NO synthesis and mast cells were less numerous. NO directly regulating the diameter of arteries and the intensity of transcapillary exchange can act as a signal molecule in the temporal dynamics of the vasoceptive action of estrogens and their receptors in the uterus.

Reaction of Mast Cells in the Zone of Polypropylene Mesh Implantation.

Reaction of mast cells of adult male Wistar rats (n=15) in the zone of polypropylene mesh fixation was studied by histochemical, immunohistochemical, and traditional morphological methods on days 1, 5, 10, and 30 after implantation. Immediately after the intervention, mast cells stimulated the processes aimed at wound healing. Secretion of mast cells was clearly regulatory. These cells migrated to the zone of injury for subsequent activation of their function. The number of cNOS+ mast cells near the polypropylene mesh was maximum on day 1 and the number of iNOS+ mast cells peaked on day 5 of the experiment, which probably represented a compensatory reaction. Presumably, stimulation of fibrillogenesis was largely due to the activatory effect of mast cells on the fibroblast function, but not to collagen production by these mast cells.

Topochemistry of Internuclear and Intranuclear Interneurons of the Vasomotor Area in the Medulla Oblongata of Hypertensive Rats.

Immunohistochemical examination with the antiserum against neuronal NO synthase and cystathionine ß-synthase was used to study the following two pools of interneurons in Wistar rats at various periods after the development of renovascular hypertension: intranuclear interneurons (lying in the projection of the solitary nucleus, reticular gigantocellular nucleus, and parvocellular nucleus) and 2 groups of internuclear interneurons (small interneurons, area 50-300 µ(2); and large interneurons, area above 350 µ(2)). Intranuclear and internuclear interneurons probably play a role in the central mechanisms of hemodynamics regulation. These interneurons differ by not only in topochemical parameters, but also functional properties (different resistances to BP changes). Intranuclear interneurons are characterized by high sensitivity of the gas transmitter systems to a continuous increase in BP, which results in remodeling and dysfunction of the bulbar part of the cardiovascular center. Large internuclear interneurons demonstrate a strong reaction to BP rise, which confirms their involvement into hemodynamics regulation. By contrast, small internuclear interneurons retain their characteristics in arterial hypertension and probably perform an integrative function.

Two pools of interneurons in the bulbar region of the cardiovascular center of rats.

Wistar rats were subjected to renovascular hypertension. Then, we studied two pools of neurons: intranuclear neurons located in projection area of the solitary tract nucleus and reticular, magnocellular, and parvicellular nuclei; and two groups of internuclear neurons, which included both small neurons 50-300 µm(2) in size and large neurons more than 350 µm(2) in size. Immunohistochemical methods with antisera against neuronal nitric oxide synthase, cystathionine-ß-synthase, and heme oxygenase-2 were used. The studies were performed 8, 16, and 24 weeks after the development of renovascular hypertension. We have found that at least two pools of interneurons, intra- and internuclear cells, may be involved in the mechanisms of regulation of hemodynamics. These pools of interneurons differ in some topochemical and functional features, including different resistances to an increased blood pressure.

[Interneurons Brainstem of the Human].

OBJECTIVE: To conduct a comparative study of the structural organization of internuclear interneurons involved in the metabolism of nitrogen monoxide, hydrogen sulphide and carbon monoxide in the caudal brain stem humans. METHODS: The cross-sectional study was performed. We used histochemical and immunohistochemical methods to study the internuclear interneurons expressing neuronal nitric oxide synthase, cystathionine ß-synthase and heme oxygenase-2 which are located between the giant and small cell reticular nuclei (cell group 1), small cell reticular nucleus and the nucleus of the solitary tract (cell group 2) or is surrounded by reticular lateral nucleus (cell group 3). RESULTS: The work was carried out on the corpses of 6 men 18-44 years old who died from causes unrelated to the damage of the central nervous system. We revealed the differences between internuclear organization and intranuclear interneurons and local structural features of internuclear interneurons that are more clearly visible between the cell group 1 including a relatively large number of large neurons and cell groups 2 and 3 (p < 0.001). In the latter two groups small cells with high concentrations of the neuronal nitric oxide synthase and heme oxygenase-2 dominated. CONCLUSION: Despite the fact that the number of internuclear interneurons significantly is less than the number of intranuclear cells, they have structural prerequisites to control integration processes in the brain. Internuclear interneurons produce gasotransmitters and classical mediators of nerve impulse, form a local chain of interneurons between vasomotor nuclei, share many links with the above and the lower parts of the brain.

Immunolocation of cystationine ß-synthase in cerebral pontile nuclei in humans.

The immunolocation of cystationine ß-synthase in the motor, sensitive, and autonomic nuclei of the cerebral pons was studied on the material from 8 healthy men aged 18-44 years dead from traumas not involving the CNS. The motor nuclei contained numerous large intensely stained cells, while the sensitive and autonomic nuclei contained many small neurons with low levels of cystationine ß-synthase marker. However, cells with intense reaction were found among small neurons. They were located mainly at the nuclear periphery, between the nuclei or between the nuclei and conduction tracts. The content of immunopositive neurons in the studied nuclei varied from 2 to 14%. The level of these cells in motor nuclei was 3-4-fold higher than in sensitive and autonomic nuclei.

Distribution of H2S synthesis enzymes in the walls of cerebral arteries in rats.

The distribution of two enzymes involved in H(2)S synthesis, cystationine ß-synthase (CBS) and cystationine γ-liase (CSE), was studied in the walls of the internal carotid artery, order I-V branches of the middle cerebral artery basin, and intracerebral vessels of adult Wistar rats. Immunohistochemical staining showed the presence of CBS in the endothelium of small pial arteries (order IV-V branches) and intracerebral arterioles and in the capillary walls, neurons, and vascular nerves. As for CSE, in the internal carotid artery and large (order I-II) pial branches it was found mainly in the tunica media myocytes, in order III-IV vessels in myocytes and endothelium, and in smaller pial and intracerebral vessels in the endothelium. Along with enzyme-positive vessels, many pial and intracerebral arteries contained no these enzymes in the walls.