Structural characteristics of renomedullary interstitial cells of hypertensive ISIAH rats.

The structural characteristics of the renal medulla and its interstitial cells were studied in hypertensive ISIAH rats (in comparison with normotensive WAG rats) in order to clear out the role of the renomedullary interstitial cells in the mechanisms of AP regulation. Morphometric electron microscopic analysis and immunohistochemical studies in ISIAH rats detected the initial signs of the renomedullary sclerosis. The renomedullary interstitial cells of ISIAH rats were characterized by higher numerical density and were larger in size, with a higher volumic share of their secretory granules.

Chromogranin location in the adrenal glands of ISIAH rats.

Comparative immunohistochemical and electron microscopic study of the adrenals from hypertensive ISIAH rats and normotensive WAG rats (control) showed a more intense reaction to chromogranin A in the ISIAH adrenal in comparison with the control. Electron microscopy and morphometric analysis showed high volume and numerical densities of the secretory granules in chromaffin cells of hypertensive rats. The results indicate stimulation of the adrenal medullary substance in ISIAH rats.

Cardiac natriuretic peptides and development of hereditary hypertension in rats.

Ultrastructure of the right atrial cardiomyocytes of suckling ISIAH rats was studied to clarify the role of cardiac natriuretic peptides in hypertension development during the period when blood pressure is not yet elevated. Cardiomyocytes diameter was significantly greater, Golgi complex was more developed, and granules in the sarcoplasm were more abundant in ISIAH rats as soon as on postnatal day 12 in comparison with age-matched normotensive animals. The smaller diameter of granules and their qualitative composition (ratio of forming, mature, and dissolving forms) attest to active synthesis and release of secretory product.

Structural characteristics of renal glomerular system in ISIAH rats under conditions of chronic stress and preventive hypotensive drug therapy.

The effects of chronic stress on the structure and function of the renal glomerular system were studied in hypertensive ISIAH rats treated with hypotensive drugs during the early ontogeny. The morphometric parameters of the renal glomerular system, characteristic of each of the experimental animal groups treated by enalapril, losartan, or terazosin in early age virtually did not change under conditions of stress exposure. These results indicate a persistent delayed nephroprotective effect of these drugs.

Structural characteristics of adenohypophysis in hypertensive ISIAH rats in early ontogeny.

Comparative morphological study of the adenohypophysis was conducted in 3-week-old normotensive WAG and hypertensive ISIAH rats (prehypertension period) to elucidate the role of the adenohypophysis in the development of essential hypertension. Morphometric analysis revealed ultrastructural signs of functional activation of somatotrophs, gonadotrophs, and corticotrophs in ISIAH rats. These peculiarities of structural organization of adenohypophysis in hypertensive rats can attest to enhanced response of the hypothalamic-pituitary-adrenal axis in these animals to natural stress associated with their transition to independent feeding.

Delayed effect of hypotensive drugs on blood pressure and structure of the myocardium in hypertensive ISIAH rats during chronic stress.

Administration of antihypertensive drugs alpha(1)-adrenoceptor antagonist and Ca(2+) channel blocker during early ontogeny had various delayed effects on blood pressure in ISIAH rats with inherited stress-induced arterial hypertension under resting conditions and chronic stress. The drugs did not prevent the development of myocardial hypertrophy. Chronic stress had little effect on myocardial structure in adult animals.

Structure of zona reticularis of adrenal cortex in hypertensive NISAG rats.

The structure of zona reticularis of the adrenal cortex in hypertensive NISAG rats was studied during the early, middle, and late periods of postnatal ontogeny. The detected morphological signs suggest that hypotrophic changes in zona reticularis of the adrenal cortex in hypertensive rats appeared before the onset of high blood pressure and accompanied the development of arterial hypertension in these animals.

Characterization of the novel chemically modified fungal polysaccharides as the macrophage stimulators.

By means of carboxymethylation, a novel water-soluble carboxymethyl chitin-glucan (CM-CG) was prepared from the mycelium of Aspergillus niger, and its ability to stimulate macrophages was assessed and compared to that of the previously studied carboxymethylated glucan (CMG) from the yeast Saccharomyces cerevisiae. It was demonstrated that single intraperitoneal (i.p.

[Morphometric characterization of hepatocytes during adaptation to extreme Antarctic factors].

The dynamics of ultrastructural changes in the hepatocytes of albino rats after prolonged influence of extreme Antarctic factors had been studied using the morphometric method. It was found that at the early stage of the experiment (7-45 days) the intracellular homeostasis in the hepatocytes was disturbed owing to a pronounced decrease in energy sources and plastic reserves (the decrease in numerical and volume density of the mitochondria, the reduction of the rough endoplasmic reticulum volume and the dilatation of its cisterns, the increase in the volume of the smooth endoplasmic reticulum). The following stages (up to 180 days) were characterized by a practically complete restoration of energy-plastic potential of the hepatocytes; at the conclusive stage of the experiment (270 days) the exhaustion of energy and, especially, of plastic reserves of the hepatocytes was noted (the significant decline in numerical density of the mitochondria and the relative volume of the rough endoplasmic reticulum).

Age-related structural characteristics of the adrenal medulla in hypertensive NISAG rats.

Structural characteristics of the adrenal medulla in hypertensive NISAG rats (hereditary stress-induced arterial hypertension) were studied during various periods of postnatal ontogeny. Signs of hyperplasia of the adrenal medulla were most pronounced in adult hypertensive animals with persistent arterial hypertension, as well as during the period of late ontogeny.

[Cardiovascular peculiarities in hypertensive rats (Hsiah strain) after antihypertensive drug intervention during juvenile period of life].

Treatment with different types of antihypertensive drugs during second month age has not prevented development of arterial hypertension and myocardial hypertrophy in the adult rats with inherited stress-induced arterial hypertension. At 6 months of age, the 11% attenuation of basal blood pressure has beet achieved only in the rats treated with angiotensin-converting enzyme inhibitor enalapril. Nevertheless, they expressed the most pronounced left ventricular hypertrophy.

Effect of enalapril injected in the early period of postnatal ontogeny on structure of adrenal glands in mature hypertensive NISAG rats.

Blood pressure in 6-month hypertensive NISAG rats daily treated with enalapril in the early postnatal period was lower than in control rats. Enalapril produced significant morphological alterations only in the zona glomerulosa of the adrenal cortex. The volumes of this area and the corresponding endocrine cells were lower than in the control.

Delayed effects of enalapril on structural characteristics of the glomerular apparatus in the kidneys of NISAG rats.

Structural characteristics of renal glomeruli were studied in adult hypertensive NISAG rats (hereditary stress-induced hypertension) receiving antihypertensive drug enalapril, an inhibitor of angiotensin-converting enzyme, on days 28-58 of life. Treatment with enalapril (25 mg/kg perorally) in the early period of postnatal ontogeny produced delayed hypotensive and nephroprotective effects.

[Stereomorphometric study of target organs in rats with hereditary stress-induced arterial hypertension at different periods of postnatal ontogenesis under changed conditions of nursing].

In rats with inherited stress-induced arterial hypertension (ISIAH strain), myocardium, adrenal gland, and renal glomerular apparatus were studied at different periods of postnatal ontogenesis (3 weeks and 6 months) to assess the influence of the changed conditions of nursing on the development of a hypertensive status and structural-functional characteristics of target organs. It was demonstrated that nursing of rats by foster normotensive Wistar females exerted a modulating influence upon the realization of stress-determined program of arterial hypertension development, seemingly delaying it and alleviating the negative consequences in respect to the target organs, through increased effectiveness of recruitment of adaptive-compensatory organism reserves, however, on the whole, it did not interrupt this program.

Effect of chronic stress during neonatal ontogeny on structural organization of the adrenal gland in hypertensive NISAG rats.

Structural organization of the adrenal gland was studied in 3-week- and 6-month-old hypertensive NISAG rats subjected to daily handling (10-min separation from mothers) on postnatal days 1-21. Neonatal handling reduces the stress-induced blood pressure rise in adult NISAG rats and modulates the structure of the adrenal cortex and medulla.

Effect of chronic stress during early postnatal ontogeny on structural characteristics of the myocardium and glomerular apparatus of the kidneys in NISAG rats.

We studied structural characteristics of the myocardium and glomerular apparatus of the kidneys in 3-week- and 6-month-old male NISAG rats (hereditary stress-induced arterial hypertension) subjected to handling on days 1-21 of postnatal ontogeny. The animals were daily isolated from mothers for 10 min. Handling did not modulate the development of arterial hypertension and typical morphological signs in the myocardium and kidneys.

[Structure of the adrenal gland in rat strain with hereditary stress-induced arterial hypertension nursed by Wistar dams].

The comparative investigation of the adrenal structure in two groups of rats of Inherited Stress-Induced Arterial Hypertension (ISIAH) strain was conducted. The animals of the first group were nursed by normotensive Wistar rats, while those of the second (control) group were reared by their own mothers. The volume of the adrenal medulla in rats of the first group was found to exceed that in the second group.

[Ultrastructural changes of kidney corpuscles in rats with hereditary stress-induced arterial hypertension].

Comparative electron microscopic study of glomerular apparatus was performed in 6-month old Wistar rats and in rat strain with inherited stress-induced arterial hypertension (ISIAH). It was shown that this stage of hypertensive status formation was characterized by hypertrophy of renal corpuscles, accompanied by structural changes of all their cellular and noncellular components. These included abrupt capillary constriction or dilation, endothelial flattening, podocyte hypertrophy and flattening of their cytopodia, thickening of basal lamina, mesangial volume expansion and increase in the number of intercapillary processes of mesangial cells.

Structure of renal glomeruli in hypertensive NISAG rats reared by normotensive females.

Morphometry of ultrastructural components of renal glomeruli in 3-week- and 6-month-old rats with hereditary stress-induced arterial hypertension (NISAG rats) reared by normotensive Wistar females showed deceleration of the development of arterial hypertension in NISAG rats and attenuated its negative consequences for kidneys as the target organs.

Chitotriosidase as a new marker of macrophage stimulation in a tumor model treated with cyclophosphamide and Ukrain.

Ukrain has previously been demonstrated to exert a malignotoxic effect in vivo. This antitumor drug has been effective in the treatment of some malignancies in experimental animals as a result of immunostimulation (macrophage stimulation). In the present study, serum chitotriosidase activity was measured as a biochemical marker of macrophage stimulation in several murine and rat models of macrophage stimulation.

[Structural characteristics of the adrenal cortex from rats with stress-induced hereditary arterial hypertension in the late postnatal ontogenesis].

The comparative investigation of the adrenal cortex in hypertensive (INHERITED STRESS-INDUCED ARTERIAL HYPERTENSION--ISIAH) and normotensive strain (Wistar) 12-months age rats was performed. The structural signs such as the lowering of the mitochondria volume involved in steroid synthesis in showed more notable age-related reduction of steroidogenesis in the adrenal glomerular and fascicular zones and in the ISIAH rats. The lowering of the cell steroidogenesis was compensated by the adrenal glomerular and fascicular zones and hypertrophy as a result the adrenocorticocytes hyperplasia.

Chitotriosidase as a marker of macrophage stimulation.

Serum chitotriosidase activity was determined in different conditions accompanied by macrophage stimulation. Stimulation of macrophages with zymosan, yeast polysaccharide carboxymethylglucan (fraction II), and lysosomotropic preparation Triton WR-1339 1.5-2.

[Changes to the hepatocytes and muscle fibers of the diaphragm during adaptation to cold under normal conditions and in combination with high-altitude hypoxia].

Comparative morphometric analysis of muscular fibres of the diaphragm and hepatocytes of albino rats was carried out in adaptation to cold (0-2 degrees C for 42 d) and to combined effect of cold and high-mountain hypoxia (2-5 degrees C temperature, 4000 m height, 40 d duration of the experiment). It was demonstrated that in adaptation to cold in normobaric conditions muscular fibres of the diaphragm develop moderate hypertrophy of mitochondria, accumulation of lipid inclusions with glycogen content remaining close control level. In combined effect of cold and high-mountain hypoxia direction of these changes was remained while their manifestation was increased.

[The protective reaction of the myocardium to ischemic damage].

The morphological and functional consequences of epinephrine-induced myocardial infarction were studied in normo- (Wistar) and hypertensive (ISIAH) rats. After experimental myocardial infarction there was an irreversible transition to the "worn-out" stage or "plastic damage" to the myocardium. Thus, myocardial hibernation in ISIAH rats anticipates and determines the development of myocardial stunning, i.