[Regional and local differences in the structural changes in arterial vessels in spontaneously hypertensive rats]. / Regionarnye i lokal'nye razlichiia strukturnykh izmenenii arterial'nykh sosudov u krys so spontannoi gipertenziei.

Structural changes of the wall of arteries with different caliber that nourish skeletal muscle, guts and cerebral cortex of 7 months spontaneously hypertensive rats (SHR) were studied. Vessels of ramification order I-II in which significant increase of thickness of media, internal elastic membrane and elastic and collagenic components of the wall occurred were shown to undergo greater changes as compared to normotensive rats (WKR). Popliteal artery displayed myocyte hypertrophy, while hypertrophy and hyperplasty of cells were seen in middle cerebral and anterior mesentric artery. In order III vessels media thickness increased only due to hyperplasty in all regions studied. In order IV vessels almost no prominent structural changes were observed. In was concluded that the nature of alterations in vascular wall of SHR is associated both with peculiarities of regional vascular bed and caliber of branches composing it.

[The participation of mast cells and serotonin-immunoreactive fibers in the innervation of the cerebral vessels]. / Uchastie tuchnykh kletok i serotonin-immunoreaktivnykh volokon v innervatsii sosudov mozga.

Interrelations between adrenergic and serotoninergic nerve fibres and mast cells located near the vascular wall were studied on total preparations of rat brain pia mater. Histochemical method with glyoxylic acid revealed the dense network of adrenergic fibres and their terminal regions with variceal endings with mast cells located next to them. Immunohistochemical methods (fluorescent and method with use of peroxidase antiperoxidase complex) with the aid of antiserum serotonin showed the content of serotonin in these cells. Distribution of serotoninergic nerve fibres resemble that of adrenergic fibres with density being significantly lower. The fibres have frequent contacts with mast cells processes. These data indicate the presence of functional connection between serotonin positive nerve fibres and the possibility of their drawings in control of blood circulation of brain.

[Structural changes in the vascular wall in vasoconstrictor and vasodilator exposures]. / Strukturnye izmeneniia stenki sosudov pri vazokonstriktornykh i vazodilatornykh vozdeistviiakh.

Noradrenaline vasoconstriction of the tail artery decreased external, internal diameters and the cross-section area of all the elements of the blood vessel wall. Papaverine vasorelaxation of the same artery increased the diameters but reduced the endothelium and adventitia areas. The data obtained suggest a close relation between the blood vessel tonus and the morphology of all the elements of the vessel wall.

[Disorders of the endothelial pavement of the vascular bed caused by denervation]. / Narusheniia éndotelial'noi vystilki krovenosnogo sosuda, vyzyvaemye denervatsiei.

The changes of endothelial surface in a tail artery at its denervation provoked by the removal of a part of adventitia have been studied with the help of scanning electron microscopy. It has been shown that the innervation didn't occur in a distal part of a vessel 10-days after the operation, there were considerable changes in the endothelial cover resulting in the protrusion of nuclear region of endothelial cells into the vessel lumen and in occurrence of spindle-like cells with long, thin projections while in the proximal part of the vessel the innervation was retaining, the endothelial surface changes being not significant. It can be concluded that the endothelial surface change is due to the switching off vascular nerve influences on a vascular wall, being not result of a postoperative injury.

[Seasonal changes in the adrenergic fibers in the wall of the microvessels of the cheek pouch of the hamster, Mesocricetus auratus]. / Sezonnye izmeneniia adrenergicheskikh volokon v stenke mikrososudov zashchechnogo meshka u khomiaka Mesocricetus auratus.

Adrenergic innervation has been investigated by fluorescent histochemical method with glyoxylic acid. Adrenergic fibers were found in summer period on the arterioles with a diameter varying from 100 to 30 micron, their fluorescence being significantly lower than that in the vessels of microcirculatory bed of the mesentery, tongue, femoral muscles of the same animal. No adrenergic fibers were revealed on the arterioles with a smaller diameter, on veins and venules. In winter period, fluorescence is completely absent from all the vessels of the cheek pouch, which may be due to the decrease in the level of catecholamines in the nerves and other tissues during hibernation.

[Structural aspects of the regulatory mechanisms of vascular reactions]. / Strukturnye aspekty reguliatornykh mekhanizmov sosudistykh reaktsii.

Using antisera against serotonin (5-OT) and neurotensin (NT) with immunofluorescence, 5-OT-immunoreactive and NT-immunoreactive nerve fibers have been detected in the walls of the femoral and pial arteries and intragastric arterioles. With electron microscopy, adrenergic and cholinergic axons were found in close anatomical proximity to some intragastric capillaries and arterioles. A possible role of the detected nerves is being discussed.

[Effect of multiple administrations of hydrocortisone on the functional activity and morphological characteristics of motor neurons]. / Vliianie mnogokratnykh vvedenii gidrokortizona na funktsional'nuiu aktivnost' i morfologicheskie kharakteristiki motoneironov.

Effects of repeated (for 5 days) injections of hydrocortisone (HC) per 1 mg dialy was studied using frogs Rana temporaria. The functional and morphological parameters of spinal motoneurones were investigated. The repeated administrations of HC diminished the excitability of spinal elements, prolonged the latency, and decreased the amplitude of ventral root potentials in response to single stimula applied to dorsal roots. Simultaneously, some structural changes occurred in motoneurones examined: swelling of the cytoplasm and the nucleus, chromatolysis of cell processes, nucleolar hypertrophy, increase in glycogen granule density, swelling of synapses. A suggestion is made that the repeated hormone administration caused in nervous cells some destructive changes of exhaustive type.

Effect of hydrocortisone on bioelectric activity and morphological pattern of spinal cord in frogs.

The effect of 1 mg hydrocortisone (HC) administered 3 h before the experiment was studied the bioelectric activity of ventral roots of spinal cord, the size and morphology of motoric neurons and also the size of synaptic endings being measured under different frequency of electric stimulation in frogs. It was found that the effect of HC on the electric activity of spinal cord and morphology of its neural elements was dependent on the stimulation used. Under the resting conditins the administration of HC resulted in a small decrease of the size of neurons. Under a low frequency stimulation HC did not affect the electric activity of spinal cord, but prevented the swelling of neurons and of synaptic endings resulting from the stimulation. Under a high frequency stimulation themorphology of neurons was remarkably changed, a shrinkage of these and an appearance of "dark" cells being found. Also these changes were prevented by the administration of HC. It was concluded that in all experiments HC prevented the changes resulting from electrostimulation, its effect, however, being dependent on the parameters of the stimulation used.