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Biomedical subjects

O A Gomazkov

Publications and source records attributed to O A Gomazkov.

At least 19 recordsLinked to original sources
PubMed1991

[The multifunctionality of regulatory peptides and the rule of "what--where--when" as a principle of their ordered action].

Consistent study of stages and history of discovery of regulatory peptides (RP) as a new class of multifunctional endogenic regulators puts forward some actual problems. A question what new notions on the manner of control of physiological functions have been introduced by RP investigation is considered. Two historical tendencies in the RP studies are estimated. A conception on peptides as multifunctional and colocated factors of neurohumoral regulation of organism was opposed to the idea of "single" substance--a regulator of "unique" function. In this connection a conception of peptide-regulatory continuum is considered and the author postulated the principle "what--where--when" as the main rule of RP well-regulated action. The statement on tissue (regional) specificity of the biogenesis processes of different RP as molecular basis of their regulatory function is grounded.

Amino Acid Sequence↗
PubMed1990

[Characteristics of physiological reactions during long-term immunization of rats with protein conjugates of angiotensin II].

The results show that during long-term immunization of rats against conjugates of angiotensin II with bovine serum albumin definite age dynamics of immune response have been observed. It was shown that the changes of physiological readings were correlated with growing of antibodies titer against angiotensin II, accordingly, as the immune response was lower, these readings return to the initial level.

Angiotensin II↗
PubMed1990

[The methodological problems of the correlation of biochemistry and physiology in current research].

An attempt to treat critically the key methodological positions of modern biochemistry, primarily, the medical biochemistry with reference to the physiologic, pathophysiologic and clinical tasks is made. The author puts forward questions: 1) if it is possible to apply traditional approaches (principles) of biochemical investigation developed on purified systems to the whole organism systems in situ and etc.; 2) if it coincides the methodical approaches of biochemistry on the one hand and physiology (pathophysiology)--on the other one, considering the mechanisms of disease development and correspondingly the assessment and choice of therapeutic methods; 3) if there exists a necessity to create a unite methodology of biochemical and physiologic knowledge as a basis of modern medical science as a whole. Some examples showing the possible ways of new methodic consideration of traditional conceptions of in vitro biochemistry are given.

Biochemistry↗
PubMed1989

[Changes in the activity of angiotensin-converting enzyme of the lung and systemic hemodynamics in spontaneously hypertensive rats under the effect of galvanic current].

It was shown, that local influence of galvanic current upon the lung angiotensin converting enzyme (ACE) in spontaneously hypertensive rats led to a decrease of systemic blood pressure in consequence of reduced peripheral vascular resistance. The development of the hemodynamic alteration was accompanied by variations of physiological and biochemical indices of the lung ACE-activity. These results indicate that the ACE-dependent processes in the lung play on important role in the mechanisms of vasoconstriction, increase in vascular resistance and development of arterial hypertension.

Animals↗
PubMed1989

[Biochemical and functional changes during immunization of rats with angiotensin II].

Angiotensin-converting enzyme (ACE) activity in serum and some brain areas, level of angiotensin I in the blood and drinking behaviour during immunization of rats against conjugate of angiotensin II with bovine serum albumin (BSA) were studied. The results show that an increase in antibodies against angiotensin II was correlated with elevated ACE activity in serum. There was a distinct tendency towards elevated level of angiotensin I in the blood. After a 6 month's immunization ACE-activity was reduced twofold to threefold in midbrain and hypothalamus-thalamus. During immunization water-uptake was increased by 40-45%.

Angiotensin I↗
PubMed1987

[Age-related and regional changes in angiotensin-converting and kinin-degrading activity in the brain of aggressive rats].

Aggressive behaviour (muricidal) induced in rats by local electrolyte lesions of septal brain area was accompanied by changes in angiotensin-converting enzyme (ACE) and total kinin-destroying activity (KDA) in different brain regions. In 2-month-old rats (30 days after septal operation) a decrease in ACE activity was observed in hypothalamus and striatum, while in the cerebellum the activity was increased. KDA in this group of aggressive rats was markedly increased in the pituitary body, hypothalamus and striatum. Half a year after septal lesion in spite of aggressive behaviour retention, ACE activity and KDA did not differ from their activity in nonmuricidal rats of the same age. These data show a distinct role of the peptides studied in the formation and maintenance of muricidal behaviour in rats of different age.

Aggression↗
PubMed1987

[Spontaneous and septal models of muricidal behavior: regional activity of enzymes regulating angiotensin and bradykinin metabolism in the brain].

Spontaneously muricidal rats (SMR) were selected from a group of white male rats. In the remaining animals muricide was induced by the local electrolyte damage of the brain septal area. Both muricidal models had different physiological indexes of aggressive reactions. In SMR a significant decrease in angiotensin-converting enzyme activity was detected in the midbrain and thalamus-hypothalamus areas. In the group of operated muricidal ("septal") rats alterations in angiotensin-converting enzyme activity have been revealed in none of the brain areas examined. The increase in total kinin-destroying activity in the pituitary, cerebellum, striatum and thalamus-hypothalamus areas was detected. The results indicate neurochemical specificity of brain angiotensin II and kinins in the regulation of different muricidal models.

Aggression↗
PubMed1987

[Metabolic function of the lungs and regulation of homeostasis].

Morphological, biochemical and pathophysiological data on the significance of the metabolic (non-respiratory) function of the lungs in the regulation of homeostasis have been summarized. The key "strategic" position of the lungs in the blood circulation system, the concentration of a unique set of biochemical regulatory factors in the lung endothelium, as well the presence of a multiple system of nervous and humoral control ensure the realization of a specific mission by lungs as a regulator of the functional integrity of the organism. The lungs serve as a barrier controlling the passage of deleterious substances into arterial blood and consequently into the brain and other organs and at the same time the lungs are responsible for the controlled synthesis and elimination of physiologically active substances essential for the work of the same systems. These functions attain special significance under stress-induced situations as a result of homeostatic disruptions and as a consequence of grave extrapulmonary injuries. The author's concept on a compensatory function of the lung kallikrein-kinin system under extreme conditions of organism is given. This pathway opens up the prospects for search of ways of correcting functional disruption in organism.

Homeostasis↗
PubMed1986

[Enzymological bases of the physiological action of regulatory peptides].

The examination of enzymes involved in the neuropeptides metabolism shows that the same substance can be hydrolysed by different peptidases. At the same time each of these enzymes can take part in destruction of different in their structure and functional significance peptides. The analysis of the conditions ensuring selective, regulating action of the definite neuropeptidases in the process of peptides formation and destruction is necessary for the understanding of the regulatory peptides physiological role. Substrate specificity of the enzyme, its localisation in some tissues and organs in brain and periphery, the organisation of enzyme or enzymatic complexes in a cell, the specific inhibitors influence are considered as such conditions. These conditions are examined for a number of peptidases involved in enkephalin metabolism, angiotensin I and II, bradykinin, substance P and others. The significance of such enzymologic approach in the investigation of regulatory peptides function is illustrated by concrete examples.

Angiotensin II↗
PubMed1985

[Regional changes in the activity of the angiotensin-converting enzyme in the brain of rats with developing hereditarily induced hypertension].

Angiotensin-converting enzyme (ACE) activity in the pituitary zone and 7 other brain areas has been studied in rats with developing spontaneous hereditary hypertension. ACE activity was significantly different in normotensive and spontaneously hypertensive rats, with the differences most prominent in pituitary body, cerebellum, striatum and medulla oblongata. Age-dependent variability in ACE activity was demonstrated.

Aging↗
PubMed1985

[Distribution of the kinin-breakdown activity in areas of the rat brain in the dynamics of spontaneous hypertension].

Kinin-damaging activity (KDA) has been studied in 8 brain areas of normotensive rats and rats with spontaneous hypertension, aged 3 to 12 months. A significant depression in KDA was revealed in midbrain, striatum, thalamus, and pituitary body of normotensive rats 6 months of age, as compared to 3-month-old animals. A tendency towards KDA increase was noted in the hypothalamus. In 12-month-old normotensive rats KDA level returned to baseline (3 months of age). Comparison of KDA in rats with spontaneous hypertension aged 3 to 12 months has revealed no age-dependent differences and it is, therefore, believed that rats with spontaneous hypertension lack certain mechanisms inducing a considerable decrease of KDA in 6-month-old normotensive rats.

Aging↗
PubMed1984

[Relation between the renin-angiotensin and kallikrein-kinin systems of the blood during physical loading of hypertension patients].

Blood angiotensin-converting enzyme, renin, kallikrein and prekallikrein ratios were investigated in 61 essentially hypertensive patients at rest and during rationed exercise. Biochemical findings were compared with major parameters of systemic hemodynamics measured under the same conditions. Grouping of patients on the basis of renin activity was mirrored in different levels of the angiotensin-converting enzyme and kallikrein: increased renin activity was accompanied by the activation of the said enzymes, and reduced activity, by their suppression. Rationed exercise did not produce noticeable kallikrein-kinin shifts in hypertensive patients, their renin-angiotensin response depending on the baseline. The markedness of hemodynamic change in response to exercise differed in patients with different humoral background.

Adult↗
PubMed1984

[Activation of the blood kallikrein-kinin system in disseminated intravascular coagulation in rats. The significance of the pulmonary component and an attempt at correction with aspirin].

It has been shown that the development in animals of disseminated intravascular coagulation (DIC) caused by long-term intravenous infusion of thrombin was accompanied by appreciable activation of the kallikrein-kinin system, being characteristic of acute pathological processes. In the initial stages of the process development, prekallikrein and kallikrein inhibitor were observed to be secreted from the lungs to arterial blood. Further development of DIC led to the depletion of the reserves of the kinin system. Pretreatment with a single low dose of acetylsalicylic acid considerably reduced the total animals' lethality and postponed blood kinin system activation determined by the development of DIC.

4-Aminobenzoic Acid↗
PubMed1984

[Importance of the thrombocyte count and form for contact activation of the blood kallikrein-kinin system in vitro].

The importance of the platelet count and intactness for contact Hageman's factor-dependent activation of blood plasma kallikrein has been demonstrated. The degree of kallikrein activation was in agreement with the count of platelets contained by the sample. Kallikrein activation was also found to be potentiated by the membrane fraction of washed platelets and of those destroyed by freezing and thawing. The cellular contents did not produce any significant effect on the activation in question.

Animals↗
PubMed1983

Vasoactive peptides and regulation of hemodynamics in different functional states of the organism.

It is important to emphasize that the biochemical systems participating in humoral hemodynamic regulation may function at any level of the circulatory homeostasis: in the blood as a biological fluid constantly circulating along the vessels, at the microcirculatory bed where the exchange with tissues is realized, on the tonic activity of the resistive and capacitance vessels, defining the systemic blood pressure rate and organ redistribution, or, finally, on the main motive force of the blood, the heart. The interrelations of some molecular factors form the biochemical basis for the interaction of the main humoral systems. These factors are kallikrein for kinins and converting enzyme for the renin-angiotensin system, 9-ketoreductase and phospholipase for kinin and prostaglandin systems, and Hageman factors for coagulation, fibrinolysis, and kininogenesis systems. This main scheme includes "functional" connections, which are defined by a physiological interaction, and those between the central and peripheral nervous systems. We may, evidently, postulate an important biological regularity of a multi-functional participation of the same physiologically active factors in maintaining circulatory homeostasis. On the other hand, we have to emphasize the functional unity and joint correlating actions of different biochemical blood systems.

Animals↗