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Biomedical subjects

O V Volkova

Publications and source records attributed to O V Volkova.

At least 19 recordsLinked to original sources
PubMed2003

Effect of bacterial endotoxin on secretion and synthesis of vasopressin during saline load in rats.

Secretion and synthesis of vasopressin was studied in adult male Wistar rats receiving lipopolysaccharide in a dose of 250 microg/100 g body weight and subjected to moderate osmotic stimulation (2% NaCl perorally for 6 days). Lipopolysaccharide stimulated secretion of vasopressin into the blood. It should be emphasized that the content of vasopressin mRNA in gigantocellular nuclei of the hypothalamus decreased, which probably reflected intensification of its translation. The observed changes and slight increase in transcription of the vasopressin gene (determined by the content of heterogeneous nuclear RNA) provide intensive secretion of this neurohormone into the blood.

Animals↗
PubMed2002

[Evolutionary aspects of a stress reaction].

Interconnections between the integrative systems, such as nervous, endocrine, and immune ones, are clearly seen during a stress response. The sources of such a cooperation should be sought at the earliest stages of evolution of multicellular organisms. The paper deals with the main points of the formation of a stress response and the development of the systems involved in this process. Based on the data available in the literature and their own findings, the authors conclude that just primitive multicellular organisms, such as coelenterates, have hemolymph cells (chemocytes) that combines the properties of all regulatory systems of more highly organized species. However, the need for such cells no longer arises afterwards. Glucocorticoids, one of the major stress hormones, show up during the development of a stress response relatively late--in fish. While in fish, the production of ACTH and glucocorticoids in the pituitary cells is under urotensin control, this function belongs to corticotropin-releasing hormone of pituitary origin in more advanced animals. The predominant value of corticotropin-releasing hormone simultaneously occurs with the development of the pituitary portal vascular system. Such transformations lead to the formation of the hierarchically arranged neuroendocrine axes that are responsible for showing a stress response, on the one hand, and to the development of qualitatively new interactions between the nervous, endocrine, and immune systems, on the other.

Animals↗
PubMed2001

[Vasopressin and inflammation].

At least three vasopressinergic brain systems are involved in inflammatory reaction. The first one is VP neurons of the bed nucleus of stria terminalis, projecting to antipyretic center in the preoptic forebrain region. The second system is neurons of the parvocellular subnucleus of the hypothalmic paraventricular nucleus. VP from these neurons reaches portal blood through the external zone of the median eminence. VP potentiates the effect of corticotropin releasing hormone on ACTH cells in the anterior pituitary. Synergetic modulation of pituitary-adrenal axis by these neurohormones maintains synthesis and release of glucocorticosteroids. The latter plays crucial role as endogenous immunosuppresants. The third VP system is magnocellular hypothalamic neurons that release vasopressin into general circulation. Systemic VP is capable of compensating the water lost caused by symptoms of inflammation. The review is devoted to analysis of current information concerning physiology and interactions between these systems during acute and chronic inflammation. The special reference has been made on the magnocellular neurons and the role of circulating vasopressin in the renal function regulation.

Adrenal Glands↗
PubMed1999

[Mechanism of ovarian follicle selection for ovulation].

Mechanisms of ovarian follicles selection for ovulation remain incompletely deciphered. Studying mechanisms of transmission of hormonal stimulatory and inhibitory signals to follicular histion somatic cells may assist in progress in this area of knowledge. The present study was aimed to detect a-subunits of G proteins (common, stimulatory, inhibitory) involved in transmission of hormonal signals to intracellular effectors and phospholipase C, initiating phosphatidyl inositol mechanism of hormonal stimuli transmission, in cryostat sections of follicles using indirect immunolabeling. A-common subunit to labeling index of granulosa layer cells correlating with the phase of follicle development was identified. A direct relationship between phospholipase C activity in granulosa layer cells of antral follicles and their size was demonstrated as well. The perspective of research in this area and their significance for the development of the theory of follicle selection is discussed.

Animals↗
PubMed1993

[Effect of hyperprolactinemia of varying origin on paracrine relationships in rat testes].

Light microscopy characteristics of mature rat testes were studied in control and hyperprolactinemia rats. The number of cells defined as granulocytes in interstitial regions adjacent to seminal ducts at stage VII and XII of spermatogenesis has been calculated. Normal deference difference between these parameters diminish in hyperprolactinemia. It is suggested that prolactin participates in intratesticular paracrine mechanisms regulation.

Animals↗
PubMed1987

[Reaction of the ovaries of 1- and 4-day-old rat pups to transplantation].

Morphofunctional peculiarities of ovarian development in 1- and 4-day-old rats have been studied under conditions of their transplantation into mature female rats. In 30 days in transplants of both series of the experiments atretic process develops. Better preservation of the general pool of the germ cells and follicles is obtained at transplantation of the ovaries from the 4-day-old donors; their ovocytes at the operation time are at the stationary state of meiosis prophase. Ovocytes of 1-day-old animals, being at the stages of early prophase, are more vulnerable at homotransplantation.

Aging↗
PubMed1987

[Carbohydrate determinants of organs of the reproductive tract of the mouse according to the results of using lectins with different specificities].

Histotopography of lectin receptor sites in adult mice ovary, oviduct, uterus, testis and epididymis has been investigated on light-optic level by means of lectin-peroxidase technique. Paraffin sections are treated with peanut agglutinin (PNA), soybean agglutinin (SBA), wheat germ agglutinin (WGA) and Laburnum anagyroides lectin (LAL), conjugated with horseradish peroxidase. Concanavalin A (Con A) receptor sites are visualized by indirect method. The usefulness of lectins for selective histochemic evaluation of definite organ structures is demonstrated. Zona pellucida, luteocytes, oviductal and uterine epitheliocytes are rich in receptor sites for all lectin used in the investigation. The most intense binding to zonae pellucidae glycoconjugates possess WGA and LAL, to luteocytes--PNA, SBA and LAL, to oviductal and uterine epitheliocytes--Con A and LAL. The preferential SBA binding to the acrosomal system and plasma membranes of spermatogenic cells is demonstrated. Changes in lectin-binding patterns during the maturation of intraovarian oocytes and spermatogenic cells are also studied. The perspectives of practical application of the results obtained, as well as trends in further lectin histochemistry investigations of the reproductive system are discussed.

Animals↗
PubMed1985

[Morphogenesis and histophysiology of the corpus luteum].

A great amount of different problems on morphogenesis and histophysiology of the corpus luteum is presented, with an emphasis on light optic and ultrastructural data that characterize the developmental dynamics of the corpus luteum. The vascular reaction is described in details, beginning from the preovulatory period. The total high vascularization rate is demonstrated and certain information on ultrastructure of newly formed capillaries and macrophages is concerned with. For the first time the authors' data on intravascular macrophages are given. The role of macrophages in the function and structural dynamics of the corpus luteum is discussed. Owing to the results obtained histochemically, ultrastructurally and biochemically, the subject on dynamics of the corpus luteum hormonoproduction, on processes participating in the hormone secretion, as well as on the role of the interstitial tissue in the corpus luteum formation is considered. The data from the literature and those of the authors are presented concerning the means and ways of progesteron transport in the form of vesicles, granules, or by means of molecular diffusion. Participation of the corpus luteum macrophages (tissue and vascular ones) in processes of synthesis and transport of progesteron is analysed. The role of prostaglandins in the chain of regulation of development, function and involution of the corpus luteum is studied. The changes in balance of prostaglandins, when prostaglandin F2 is administered result in decreasing amount of progesterone in blood. In the experiment, synthesis of prostaglandins is blocked by indometacin administration and it causes certain disturbances in luteal transformation.

3-Hydroxysteroid Dehydrogenases↗