[Blood flow dynamics in adjacent microvessels of the brain in hypertensive rats]. / Dinamika krovotoka v blizkoraspolozhennykh mikrososudakh mozga gipertenzivnykh krys.

Significant alterations in the blood flow velocity, its amplitude and oscillations were found in cerebral cortex's microvessels of 5-12 mu diameter in normotensive and spontaneously hypertensive rats. Associated alterations of the blood flow shifted by a few seconds, were found in adjacent vessels. These alterations seem to be due to hemodynamic readjustments in proximal parts of the vascular net. The absence of these alterations in adjacent vessels suggests no significant redistribution of the blood flow in resting in cerebral cortex's microvessels.

[Effect of the ion composition and osmotic properties of blood plasma on the erythrocytes of normotensive and hypertensive rats]. / Vliianie ionnogo sostava i osmoticheskikh svoistv plazmy krovi na éritrotsity normo- i gipertenzivnykh krys.

Size of the erythrocytes was shown to change depending on the osmolality of "own" plasma in normotensive rats (WKY). Size of the erythrocytes was unaltered in hypoosmotic (the H2O load) and enhanced in hyperosmotic (the NaCl load) and isoosmotic (the KCl load) media in hypertensive rats (SHR). These specific properties of the erythrocytes are supposed to be due to differences in the transport mechanisms of ion transition through membranes.

[Rate of blood flow in the microvessels of the brain of the rat with spontaneous arterial hypertension]. / Skorost' krovotoka v mikrososudakh mozga krys so spontannoi arterial'noi gipertenziei.

In normal and hypertensive rats, hematological indices were studied as well as the linear blood flow velocity in the microvessels with diameter 6-12 mu. Both groups of animals were shown to develop obvious oscillations of the blood velocity coinciding neither with heart beats nor with respiratory movements. In rats with spontaneous arterial hypertension, the mean velocity was 844 mu/sec and the amplitude of blood flow oscillations was 175 mu/sec which was higher by 35% and 33.5% resp. than in control animals. The erythrocyte concentration, hematocrit value and the amount of hemoglobin were higher by 11, 26 and 20% resp. in hypertensive animals. The revealed differences of the blood flow in hypertensive rats are due to the increased blood pressure, specific architectonics of the vascular bed and to changes of the blood rheological features.

[Mechanism of development of erythrocytosis in spontaneous arterial hypertension in rats]. / O mekhanizme razvitiia eritrotsitoza pri spontannoi arterial'noi gipertenzii u krys.

Rats with spontaneous hypertension versus normotensive rats showed the development of erythrocytosis, an intensification of the erythropoietic properties of the blood plasma and an increase of the 2,3-DPG concentration in the red blood cells. An enhanced production of erythropoietin, a humoral stimulator of erythropoiesis, seems to be one of the causes of the erythrocytosis development in spontaneously hypertensive rats. An increase in the 2,3-DPG concentration in the erythrocytes is an important physiological mechanism ensuring the appropriate oxygen supply to tissues.