-
[show abstract]
[hide abstract]
ABSTRACT: 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. Presumably, intensive accumulation of chromogranin A and secretory granules in chromaffin cells of hypertensive rats reflects a certain imbalance of chromogranin A and catecholamines biogenesis, this, in turn, leading to stable stimulation of the sympathoadrenal component and higher stress sensitivity of these animals.
Bulletin of Experimental Biology and Medicine 12/2012; 154(3):393-395. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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. In 21-day-old ISIAH rats, granule size and qualitative composition reflected increased accumulation of hormones in the cells. Thus, morphological features of increased production of natriuretic peptides in the right atrial myocytes were revealed in rats during the first postnatal month before manifestation of hereditary hypertension.
Bulletin of Experimental Biology and Medicine 09/2012; 153(5):771-4. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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.
Bulletin of Experimental Biology and Medicine 12/2011; 152(2):249-52. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Secretory activity of the adrenal cortex and hormonal reaction to emotional stress were examined in normotensive WAG and hypertensive ISIAH rats. Under nembutal narcosis (surgical stage), secretion of corticosteroid hormones and hormonal reaction to acute stress in hypertensive rats were enhanced. In these rats, the stress-induced elevation of aldosterone secretion was most pronounced, which indicates an important contribution of this hormone to the pathogenesis of stress-dependent arterial hypertension.
Bulletin of Experimental Biology and Medicine 12/2011; 152(2):188-91. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Comparative morphometrical study of the renal glomerular system was carried out in hypertensive NISAG rats treated with hypotensive drugs during the prepubertal period. Blockade of the renin-angiotensin system with enalapril or losartan during the critical period of ontogeny (the 2nd month of life) produced a long-term hypotensive and renoprotective effect. Treatment with alpha-adrenoblocker terazosin during this period of ontogeny produced a less pronounced hypotensive effect, though with renoprotection. Corinfar (Ca2+ channel blocker) was least effective.
Bulletin of Experimental Biology and Medicine 07/2007; 143(6):749-52. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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.
Bulletin of Experimental Biology and Medicine 01/2007; 142(6):651-3. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: NISAG rats with stress-induced arterial hypertension are characterized by hyperactivity of the sympathoadrenal system under rest conditions and during stress exposure.
Bulletin of Experimental Biology and Medicine 04/2006; 141(3):275-7. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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.
Bulletin of Experimental Biology and Medicine 03/2006; 141(2):167-9. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Electron microscopy and stereomorphometric analysis of hypertrophic cardiomyocytes in the right atrium of NISAG rats revealed signs of activation of biosynthetic processes: increased relative volume of euchromatin (compared to Wistar rats), high density of nuclear pores, presence of large numerous Golgi complexes, and well-developed endoplasmic reticulum. The numerical density of secretory granules in the cytoplasm of cardiomyocytes in NISAG rats significantly surpassed that in Wistar rats. However, these granules in NISAG rats were smaller than in Wistar rats. The presence of numerous secretory granules and increased ratio of forming and dissolving structures suggest that this pool is characterized by high turnover rate, i.e., intensive synthesis and rapid elimination (consumption) of natriuretic peptide. Hypertrophy and hyperactivity of endocrine function in atrial cardiomyocytes of NISAG rats can be considered as a compensatory reaction to hypertension.
Bulletin of Experimental Biology and Medicine 08/2004; 138(1):1-4. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: NISAG rats were subjected to handling on days 1-21 after birth. Blood pressure and plasma corticosterone concentration were measured in 6-month-old handled and control NISAG rats at rest and under stress conditions. Animal behavior was studied in the open-field test. Handling had no effect on body weight and relative weights of the heart and adrenal glands. In rats subjected to handling, changes in blood pressure and adrenal cortex produced by acute emotional stress (30-min restriction) were less pronounced than in control animals. Handled rats demonstrated less fear in a new environment and exhibited high exploratory activity in the open-field test. Our findings suggest that neonatal handling reduces stress reactivity and decreases the severity of hypertension in adult NISAG rats.
Bulletin of Experimental Biology and Medicine 05/2004; 137(4):345-7. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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.
Bulletin of Experimental Biology and Medicine 02/2004; 137(1):10-2. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: NISAG rats were subjected to handling on days 1-21 after birth. Blood pressure and plasma corticosterone concentration were measured in 6-month-old handled and control NISAG rats at rest and under stress conditions. Animal behavior was studied in the open-field test. Handling had no effect on body weight and relative weights of the heart and adrenal glands. In rats subjected to handling, changes in blood pressure and adrenal cortex produced by acute emotional stress (30-min restriction) were less pronounced than in control animals. Handled rats demonstrated less fear in a new environment and exhibited high exploratory activity in the open-field test. Our findings suggest that neonatal handling reduces stress reactivity and decreases the severity of hypertension in adult NISAG rats.
Bulletin of Experimental Biology and Medicine 01/2004; 137(4):345-347. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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.
Bulletin of Experimental Biology and Medicine 12/2003; 137(1):10-12. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We compared the results of clinical and experimental studies of endocrine parameters in patients with myocardial infarction and arterial hypertension and NISAG rats with hereditary stress-induced arterial hypertension during experimental myocardial infarction. Changes in the content of corticosterone, aldosterone, insulin, triiodothyronine, and thyroxin were similar in animals and patients with myocardial infarction and arterial hypertension. The disadaptive course of myocardial infarction against the background of arterial hypertension can be explained by reduced compensatory capacity of the myocardium.
Bulletin of Experimental Biology and Medicine 12/2003; 136(5):444-7. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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.
Bulletin of Experimental Biology and Medicine 08/2003; 136(1):22-5. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Plasma, lymph and myocardial Fe(2+) contents and blood antioxidant activity were studied in hypertensive NISAG and normotensive Wistar rats with experimental myocardial infarction. In hypertensive rats, iron levels in plasma, lymph and myocardial tissue were increased throughout the experiment. In both strains iron content in the plasma during experimental myocardial infarction negatively correlated with blood antioxidant activity. In hypertensive NISAG rats this correlation persisted also during recovery. This attests to prooxidant effect of Fe(2+) aggravating the course of myocardial infarction in NISAG rats.
Bulletin of Experimental Biology and Medicine 12/2001; 132(5):1041-4. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Morphometric analysis revealed no signs of myocardial hypertrophy at the tissue and ultrastructural levels in 3-week-old NISAG rat pups reared by normotensive Wistar females. The severity of myocardial hypertrophy in these animals aging 6 months was similar to that in NISAG rats reared by natural mothers. However, raising conditions during the early ontogeny form compensatory structural changes in the myocardium of rats with genetically determined hypertension.
Bulletin of Experimental Biology and Medicine 10/2001; 132(3):895-7. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Parameters of the cardiovascular system and the content of corticosterone, thyrotrophin, thyroxin, and triiodothyronine in the plasma, and norepinephrine in the myocardium were determined in male NISAG rats (hereditary stress-induced arterial hypertension) reared by normotensive Wistar rats. Cross-rearing of hypertensive rat pups by normotensive females attenuated arterial hypertension with a tendency to normalization of the examined parameters. This confirms the possibility of modifying hypertensive phenotype by changing the conditions of the early postnatal development.
Bulletin of Experimental Biology and Medicine 09/2001; 132(2):734-6. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Morphometric analysis revealed no signs of myocardial hypertrophy at the tissue and ultrastructural levels in 3-week-old NISAG rat pups reared by normotensive Wistar females. The severity of myocardial hypertrophy in these animals aging 6 months was similar to that in NISAG rats reared by natural mothers. However, raising conditions during the early ontogeny form compensatory structural changes in the myocardium of rats with genetically determined hypertension.
Bulletin of Experimental Biology and Medicine 08/2001; 132(3):895-897. · 0.27 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The dynamics of selenium content in the plasma, lymph, and myocardium and plasma antioxidant activity were studied in male NISAG (hereditary stress-induced arterial hypertension) and Wistar rats with acute myocardial infarction and during recovery. In NISAG rats the decrease in selenium content correlated with the decrease in antioxidant activity. This probably aggravates the symptoms of experimental myocardial infarction in animals with hereditary arterial hypertension.
Bulletin of Experimental Biology and Medicine 08/2001; 132(1):641-3. · 0.27 Impact Factor
