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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
PubMed1998

[Peptide mediators in adrenal chromaffin cells: regulation of catecholamine selective secretion].

The data obtained suggest a potential mechanism that may account for the selective control of adrenaline and noradrenaline release from adrenal chromaffin cells. Some neuropeptides seem to affect in a different way the release from A- and NA-adrenal cells by means of regulating a set of cytochemical events: specific reception of cholinergic transmitters, expression of the second messenger system including cGMP and changes in Ca channels activity, changes in the catecholamine biosynthesis in adrenal chromaffin cells. Modulating function of substance P, endothelins, PACAP, and ANF, is discussed.

Adrenal Glands↗
PubMed1998

Endothelin-converting enzyme: its functional aspect.

The system of endothelin peptides and their structure, biological activity, and role in physiological and pathological processes are reviewed with emphasis on endothelin-converting enzyme (ECE), which catalyzes the terminal processing of endothelin. Molecular specificity, structure, isoforms, physicochemical characteristics, substrate preference, and tissue localization characterize this enzyme as a novel and highly important metalloendopeptidase. The role of ECE in pathological processes and data on inhibitors of the enzyme which can have medical implication are summarized.

Amino Acid Sequence↗
PubMed1997

Effect of new peptide inhibitors on the ratio of angiotensin I-converting and kinin-degrading activities of dipeptidyl carboxypeptidase (angiotensin-converting enzyme).

The effect of N(alpha)-carboxyalkylated dipeptides on angiotensin-converting and kinin-degrading activity of angiotensin-converting enzyme (ACE, dipeptidyl carboxypeptidase) was studied. These inhibitors selectively affected ACE-induced hydrolysis of angiotensin I-like and bradykinin-like (hippuryl-His-Leu and hippuryl-Phe-Arg, respectively) substrates in microsomal fractions of rat lungs and kidneys and rat blood serum. The inhibition constants of both types of activity were determined for these enzyme preparations and also for ACE from porcine seminal fluid and highly purified ACE from porcine lung. In all cases high inhibition selectivity of angiotensin-generating and kininase activities of ACE was found.

Angiotensin I↗
PubMed1994

[A new fluorogenic substrate of carboxypeptidase H--o-coumaroylphenylalanyl-alanyl-arginine].

New fluorogenic substrate of carboxypeptidase H, Cum-Phe-Ala-Arg-OH, is hydrolyzed by this enzyme to give Cum-Phe-Ala-OH, which is completely extracted by chloroform from the reaction mixture and whose fluorescence increases remarkably by the presence of triethylamine. When the hydrolysis of the novel substrate is compared with Dns-Phe-Ala-Arg-OH, the former has Km twice as low (30 microM) and kcat four times as high (5.8 s-1). Activation of the enzyme by Co2+ in reactions with the two substrates was also studied. The novel substrate is useful for the enzyme's assay in homogenates of various animal tissues.

Amino Acid Sequence↗
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↗