PubMed Health⌕ Search

Biomedical subjects

L A Kuznetsova

Publications and source records attributed to L A Kuznetsova.

At least 37 records · Page 2Linked to original sources
PubMed1995

Involvement of the adenylyl cyclase signaling system in the action of insulin and mollusk insulin-like peptide.

Involvement of the adenylyl cyclase signaling system in the mechanism of action of the mammalian insulin and epidermal growth factor as well as of insulin-like peptide isolated from the bivalve mollusk Anodonta cygnea has been studied. It was shown for the first time that insulin and insulin-like peptide exert in vitro the GTP-dependent stimulating action on the adenylyl cyclase activity. Epidermal growth factor has an analogous effect. Effectiveness of the peptides decreased in the order insulin-like peptide > epidermal growth factor > insulin in the foot smooth muscles of A. cygnea and insulin > epidermal growth factor > insulin-like peptide in the skeletal muscles of rat.

Adenylyl Cyclases↗
PubMed1991

[Participation of gangliosides in protection of beta adrenergic receptors from damaging effect induced by lipid peroxidation in synaptosome membranes].

The induction of lipid peroxidation (LPO) in rat brain synaptosomes was shown to result in considerable decrease of the level of specific [3H]-dihydroalprenolol binding, decrease of Bmax and increase of KD. It was revealed that the preincubation of rat brain synaptosomes with monosialoganglioside GM1 (10(-8) M) or alpha-tocopherol (10(-6) M) led to a decrease in MDA accumulation after LPO induction by Fe(2+)-ascorbate system. AT the same time GM1 prevents damage of beta-adrenoreceptors, caused by LPO induction, having no effect on the functional state of beta-adrenoreceptors in control preparations. Partial normalization of the ligand affinity of the receptors was observed after preincubation of synaptosomes with GM1 and alpha-tocopherol. The various mechanisms of stabilization of synaptosomal membranes by gangliosides and natural antioxidant-tocopherol is suggested.

Animals↗
PubMed1991

[The morbidity characteristics of workers in an information reference service employed at video terminals].

Female telephone operators working with displays perform monotonous operations which cause marked hypodynamia. A study was performed to investigate the labour conditions, which revealed respiratory diseases as the main cause of morbidity with temporary disability. Extensive medical examinations also showed the prevalence of gynaecological disorders resulting from the working posture and hypodynamia. Laboratory tests revealed marked changes in the peripheral blood system. The questionnaire analysis performed showed the prevalence of complaints of asthenic manifestations and excessive fatigability by the end of the working shift.

Absenteeism↗
PubMed1990

[A comparative study of the biogenic amine receptors in the muscle tissue of mollusks, echinoderms and tunicates].

Smooth muscles of Mollusca, Echinodermata and Tunicata contain one class of adrenoreceptors with the dissociation constant and maximal specific binding 2.5 and 82 in Anodonta, 2.3 and 320 in Holothuria, 4.9 pM and 232.5 fmol/mg of protein in ascidia. Catecholamines and their antagonists can be ranged in the row as follows: isoproterenol greater than adrenalin greater than propranolol-noradrenaline greater than phentolamine. Negative regulation of the beta-adrenoreceptor affinity to isoproterenol by means of guanine nucleotides (GN) was shown. The muscular tissues of Mollusca, Echinodermata and Tunicata have only one class of the serotonin receptors with the dissociation constant and maximal specific binding 120 and 13.2 in Anodonta, 88 and 192 in Holothuria, 2.6 pM and 54 fmol/mg of protein in ascidia. The GTP negative regulation of serotonin receptors affinity to the hormone was found. The GN regulation of the above receptors affinity to agonist suggests that muscle tissue of the above species has specific GTP [correction of GTR]-binding proteins capable of coupling with these receptors.

Animals↗
PubMed1990

[Effects of alpha tocopherol and free fatty acids on physical properties of lipid matrix and adenylate cyclase activity in rat brain synaptosomes].

Using modification of physical state of synaptosome lipid matrix by free fatty acids and alpha-tocopherol it was shown that fluidity of lipid matrix isn't limiting regulating factor for the activity of alpha-adrenergic aden late cyclase. From the point of view that state of annular lipids is different from the state of lipid bilayer in synaptosomes we suggest that composition of annular lipids regulates alpha-adrenergic adenylate cyclase system in rat neuronal membranes.

Adenylyl Cyclases↗
PubMed1989

[Lack of negative regulation of beta-adrenoreceptor affinity by guanine nucleotides in embryonic membranes and its induction by the GTP-binding protein from mature protein].

The negative regulation of the beta-adrenoreceptor affinity by guanine nucleotides in the sarcolemmal fraction of chicken skeletal muscle at different stages of ontogenesis was studied. It was found that the negative regulation is absent in the embryonic period; the effect of GTP is manifested only before hatching, whereas that of Gpp(NH)p--at later periods, i.e., in 1-month-old chickens. Similar age-dependent dynamics was revealed with respect to the GTP effect on the dissociation rate of the [3H]DHA-beta-adrenoreceptor complex. An addition to the system containing embryonic muscle membranes of the GTP-binding protein isolated from skeletal muscle and liver of chickens whose age exceeds 20 days led to earlier manifestations of the above effects (on the 13th-15th embryonic days). The data obtained testify to the limiting role of GTP-binding proteins in the negative control of the hormone-receptor interaction and support the authors' hypothesis on the absence in the embryonic muscle of the 42 kD GTP-binding protein responsible for the functional coupling of the hormone-sensitive adenylate cyclase components.

Aging↗
PubMed1988

[Level of specific binding of beta-adrenergic ligands and the morphofunctional properties of erythrocytes in bronchial asthma].

Peripheral blood erythrocytes of patients with bronchial asthma (BA) and preasthma (PA) were investigated using the following methods: 1) the radiochemical method--the level of specific binding of beta-adrenergic ligands; 2) direct erythrocytometry--erythrocyte diameter; 3) the cytochemical method (paraldehyde fuchsine/PAF/-reaction)--membranous glycoproteins. The level of erythrocytic specific binding of beta-adrenergic ligands was decreased in BA and PA patients. The level of small size erythrocytes (SSE) was on an increase in patients with atopic BA, extrapulmonary allergoses as well as in healthy persons with aggravated atopic heredity. The content of PAF-negative erythrocytes turned out to be considerably raised in atopic BA. A conclusion was made of general disorders of the membranoreceptor system as a fundamental cause of allergically changed reactivity.

Adolescent↗
PubMed1988

[Effects of phospholipase A2 and alpha-tocopherol on the activity of adenylate cyclase of rat brain synaptosomes].

The action of phospholipase A2 and alpha-tocopherol on adenylate cyclase system functioning and on the lipid bilayer microviscosity of the rat brain synaptosome membranes was investigated. It was shown that the exposure of the synaptosomes to phospholipase A2 increases the adenylate cyclase activity stimulated by guanylyl imidotriphosphate (GITP), decreases the adenylate cyclase activity stimulated both by isoproterenol and by isoproterenol with GITP. The preincubation of synaptosomes in medium containing alpha-tocopherol does not change the character of the phospholipase action on the adenylate cyclase activity stimulated by isoproterenol but normalizes the adenylate cyclase activity stimulated both by GITP and by GITP with isoproterenol. In the last case the normalizing action of alpha-tocopherol is not caused by alteration of the microviscosity of the lipid bilayer. It appears to be due to the modification of the lipid-protein interactions of annular lipids with activated complex of catalytic subunit and guanyl nucleotide-binding protein.

Adenylyl Cyclases↗
PubMed1985

[Functional characteristics of the adenylate cyclase system of developing skeletal muscles in the rat].

The functional development of hormone-sensitive adenylate cyclase system of rat skeletal muscles was studied. It was shown that within 15-17 embryonic days the plasma membrane of the muscle cell contains catecholamine-sensitive adenylate cyclase (isoproterenol greater than epinephrine greater than norepinephrine) which on these ontogenetic stages is represented by functionally active catalytic, regulatory and receptory components. The coupling component, which, according to the authors' view, is presumably an independent (fourth) functional subunit of adenylate cyclase system, is formed only in the postnatal period. A suggestion is put forward that the above process is due to the fact that guanyl nucleotide-binding protein(s) responsible in the mature target cell for the coupling of receptory and catalytic components may appear in the membrane only after birth.

Adenylyl Cyclases↗
PubMed1982

[Functional properties of the catecholamine-sensitive adenyl cyclase system in embryonic skeletal muscle].

During embryogenesis the adenylate cyclase from chicken skeletal muscle possesses a high catalytic activity in comparison with the mature tissue. The embryonic muscle enzyme is sensitive to the stimulating effects of fluoride, vanadate and guanyl nucleotides. The enzyme sensitivity to catecholamines appears at the end of the 2nd week of embryogenesis. Activation of chicken skeletal muscle adenylate cyclase by catecholamines occurs via the adrenoreceptor of the beta-type. Upon combined action of guanyl nucleotides and adrenaline the potentiation effect typical for the mature muscle is observed only at post-embryonic stages. It is assumed that the functional development of the catecholamine--sensitive adenylate cyclase system in embryogenesis occurs in the following order: catalytic, regulatory, receptor components. The process is completed at the post-embryonic stage.

Adenylyl Cyclases↗