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Biomedical subjects

A L Markel'

Publications and source records attributed to A L Markel'.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Behavior and evolution].

Main works of D.K. Belyaev on genetic and evolutionary aspects of behavior are reviewed. Principal trends in development of this problem in modern science are considered. The role of Darwinian evolution in formation of human and animal behavior and evolutionary significance of behavior are discussed.

Animals↗
PubMed1996

[The brain catecholaminergic system during the long-term correction of hereditary arterial hypertension].

L-DOPA administration to 21--25-day-old rats with inherited stress-induced arterial hypertension (ISIAH rats)lowered arterial pressure both at rest and in emotional stress in adult rats. The effect seems to be due to enhancement of the brain catecholamine synthesis rather than the peripheral one in early ontogenesis. The long-term hypotensive effect of the L-DOPA was supposed to be caused in part by changes revealed in the brain catecholaminergic system.

Animals↗
PubMed1996

[Brain catecholamines and the hypothalamo-hypophyseal-adrenocortical system in hereditary arterial hypertension].

Central catecholaminergic mechanisms regulating hypothalamic-pituitary-adrenocortical system (HPAS) and arterial blood pressure (ABP) are closely related. In adult rats with inherited stress-induced arterial hypertension (ISIAH rats), response of the HPAS to emotional stress is diminished. At the same time, the level and metabolic rate of noradrenaline (NA) in many brain regions taking part in the HPAS and ABP control are decreased, and the number of alpha 1-adrenoceptors in the medulla is elevated. Age-dependent changes and interstrain differences in basal and stress-induced plasma corticosterone levels and brain noradrenaline were studied at the age from 2 up to 18 weeks in ISIAH rats and normotensive Wistar rats. It was found that the 4th week of life in the ISIAH rats is a critical period in the development of inherited hypertension. At this time, fast forming of the hypertension is accompanied by an increase in adrenocortical stress responsivity and a fall in the medulla and hypothalamic NA contents. A short-term augmentation of the brain NA synthesis on the 4th week by L-DOPA and carbidopa treatment in the ISIAH rats was followed by a normalization of the arterial pressure and pituitary-adrenocortical function in adult animals accompanied by restoration of hypothalamic and medulla NA levels and medulla alpha 1-adrenoceptor number.

Aging↗
PubMed1996

[Studies of in vitro and in vivo derived 1,2-diazetine and nitronylnitroxide as donors and acceptors of nitric oxide].

The series of nitronylnitroxyl radicals (NNR) were studied as paramagnetic scavengers of nitric oxide. These radicals react with NO with rate constants of (0.6-1.1).10(4) M-1.sec-1 forming stable iminonitroxyl radicals. They can be used to assay nitric oxide in solutions by EPR spectroscopy; the sensitivity of the method is 1 microM for the detection of NO concentration and 0.3 nM/sec for the measurements of the rates of NO generation for 1 h in 0.2 ml sample. To overcome fast reduction of the radicals in biological samples, charged NNR was incorporated into the inner volume of large unilamellar phosphatidylcholine liposomes thus decreasing the rates of NNR reduction about 1000-fold. The method was used for the NO synthase activity assay in rat cerebellum cytosol. NNR was used to study the kinetics of the decomposition of 3,4-dihydro-1,2-diazete 1,2-dioxides (DD). Several DD derivatives at 5-80 microM concentrations are very effective vasodilators in perfused rat tail artery. Intraperitoneal injection of several DD (40-200 micrograms/kg weight). in hereditary hypertensive rats (ISIAH-strain) significantly (by 30%) decreased systolic arterial blood pressure whereas similar effect of trinitroglycerin was detected at significantly higher dose (900 micrograms/kg weight).

Animals↗
PubMed1996

[Characterization of rat lines with normotensive and hypertensive status using genomic fingerprinting].

The properties of normotensive and hypertensive rat lines were investigated by the DNA fingerprinting method using a multilocus micro-satellite (CAC)5 probe. The HaeIII and HinfI restriction endonucleases were found to be the most informative enzymes in this case. The high genetic homogeneity of the ISIAH line, a rat line with inherited stress-sensitive arterial hypertension created at the Institute of Cytology and Genetics, was demonstrated. The lack of intralinear polymorphism was also typical to Japanese SHR rats with spontaneous arterial hypertension. Normotensive WAG rats had identical fingerprinting patterns, while the relative intensity of some bands was different. The outbred normotensive Wistar line maintained at the Institute, appeared to carry 30% polymorphic alleles. Hypertensive lines differed from the normotensive by a number of genetic markers.

Animals↗
PubMed1996

[The morphofunctional characteristics of the zona glomerulosa of the adrenal cortex in rats with hereditary stress-induced arterial hypertension].

Morphometrical analysis of adrenal cortex glomerular zone performed in rats with hereditary stress-induced arterial hypertension assisted in establishing important peculiarities of the zone structure. Adrenocorticocytes of adrenal cortex glomerular zone in hypertension rats are subjected to hyperplastic intercellular changes, suggesting the increase of the zone functional activity, which is substantiated by data on significantly high aldosterone concentration in plasma of these animals.

Aldosterone↗
PubMed1993

[The effects of cryopreservation and embryo transplantation on the arterial pressure value in HSIAH strain rats with hereditarily induced arterial hypertension].

Homogeneous transplantation of embryos tissue exerted no effect on arterial pressure in adult Wistar rats and slightly increased the pressure in ISIAH male rats. Transplantation of male embryos of the ISIAH strain to Wistar rats significantly increased the blood pressure in the male ISIAH rats. Female ISIAH rats seem to possess a mechanism restricting the upper limit of the blood pressure. Cryopreservation of the ISIAH embryos seems to be a potent procedure for decreasing the blood pressure in this strain of hypertensive rats.

Animals↗
PubMed1992

[Genetic correlation between the arterial pressure response during emotional stress and the alpha1-adrenoreceptor concentration in brain regions].

Arterial blood pressure reactivity to the emotional stress and brain alpha 1-adrenoreceptors concentrations were studied in hypertensive (ISIAH strain) and normotensive (Wistar strain) rats and their F1 and F2 hybrids. Significant correlations between the stress-induced increase in the arterial blood pressure and the amount of alpha 1-adrenoreceptors in hypothalamus (+0.46) and medulla (+0.38) were found in the F2. This cosegregation may point to the significant role of genetically determined peculiarities of expression of alpha 1-adrenoreceptors in brain regions during pathogenesis of arterial hypertension in the ISIAH strain.

Animals↗
PubMed1992

[Study of blood and lymph in experimental myocardial ischemia and arterial hypertension].

The peripheral blood and central lymph of rats under experimental myocardial infarction was studied by means of light microscopy and electric conductivity measurement. Both hypertensive rats and animals 3 days after myocardial infarction had similar quantity of neutrophils in peripheral blood. Lymph cells count of hypertensive rats by middle lymphocytes is similar to the animals 1 day after myocardial infarction. The correlation between lymph and blood electric conductivity and its cell composition was noted.

Animals↗