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Biomedical subjects

V P Komissarenko

Publications and source records attributed to V P Komissarenko.

At least 19 recordsLinked to original sources
PubMed1990

[Effects of desoxycorticosterone on 5-nucleotidase and adenosine deaminase activity in the hypothalamus and hippocampus of the rat brain].

Influence of single (enzyme activities was determined 5h after the preparation) and multiple (for 7 days) DOCA administration on 5'-nucleotidase (EC 3.1.3.5) and adenosine deaminase (ES 3.5.4.4) activities in homogenate and subcellular fractions of the hypothalamus and hippocampus of the rat brain has been studied. It has been shown that DOCA enhances adenosine metabolism in the hypothalamus activating both the enzymes while in the hippocampus 5'-nucleotidase activity increases whereas adenosine deaminase activity decreases. Possible ways of mineralocorticoid effects on adenosine system and the role of this nucleoside in these hormones mechanism of action on CNS functional activity are being discussed.

5'-Nucleotidase↗
PubMed1986

[Effect of mineralocorticoids on the Na, K-ATPase activity of the rat brain].

The effect of desoxycorticosterone (DOC) on Na, K-ATPase activity was studied in vivo and in vitro on microsomal rat brain fractions. An hour after intramuscular administration of DOC a noticeable increase in the enzyme activity was observed. Preincubation of microsomal brain fractions with 5 and 15 mkg/ml of DOC caused a decrease in Na, K-ATPase activity, with the results evident 3-5 minutes after the addition of the hormone into the incubation medium. The idea of a two-phase hormonal effect is suggested. It is likely that desoxycorticosterone effect is realized both by the direct influence, on Na, K-ATPase of the brain plasma membrane and by the influence on the biosynthesis.

Animals↗
PubMed1985

[Na, K-ATPase activity of the microsomal fraction of the rat brain exposed to insulin].

The effect of insulin on the activity of Na, K-ATPase was studied in rat brain microsomes. Addition of insulin to the incubation medium in a dose of 0.18 U/ml coupled with strophanthine did not change the enzyme activity. The raising of the hormone dose to 0.36 U/ml was accompanied by inhibition of the enzyme activity. The incubation duration (10 and 30 min) did not influence the Na-pump. Preincubation of brain microsomes with insulin for 5 min significantly activated Na, K-ATPase. It has been thus demonstrated that insulin is capable of influencing the activity of Na, K-ATPase of rat brain microsomes in vitro. The effect obtained depends both on the dose of the hormone introduced into the incubation medium and the experimental conditions.

Animals↗
PubMed1985

[Absence of the reaction of insulin receptors to receptorotropic activity in the rat liver with innervation lesions].

Section of the hepatic nervous plexus did not affect insulin receptor parameters in hepatic or adipose tissue plasma membranes. In control rats, the increase of the receptor insulin binding in fasting and its fall under experimental hyperinsulinemia were found both in hepatic and adipose tissue membranes, while in the rats with lesioned hepatic innervation these changes only occurred in adipose tissue membranes. No insulin receptor response to fasting or hyperinsulinemia in the rat liver with lesioned innervation occurred. The vegetative nervous system seems to affect the insulin receptors in the insulin target tissues. The nervous regulation of the receptors in addition to the humoral one, increases the effectiveness of the insulin metabolic control in its target cells.

Adipose Tissue↗
PubMed1984

[Effect of corticotropin and hydrocortisone on the cyclic AMP content and phosphodiesterase activity in the skeletal and smooth muscles of rats].

A study was made of the influence of ACTH and hydrocortisone on cAMP content and phosphodiesterase (PDE) activity in the rat gastrocnemius and gastric skeletal muscles. One and 3 hours after injection hydrocortisone caused a decrease in PDE activity and raised cAMP content in both the muscles. ACTH in a dose of 1 Unit/100 g did not change PDE activity but increased cAMP content in the muscles one hour after injection, with an elevation in the blood corticosteroid level being insignificant. Three hours after injection of 2 Units/100 g ACTH, PDE activity dropped and muscle cAMP content ascended, with an appreciable increase in the blood corticosteroid level. In the smooth muscles, PDE activity was inhibited by corticosteroids to a greater degree than in the skeletal muscles.

11-Hydroxycorticosteroids↗
PubMed1982

[Effect of a varying corticosteroid allowance on the cAMP content of limbic system structures of the rat brain].

A study was made of the effect of adrenalectomy and substitution therapy in the absence of adrenals on the cAMP content in the hypothalamus, hippocamp and striate body of the rat brain. It was shown that in sham adrenalectomized animals, the concentration of cAMP in the brain structures under study did not differ from the characteristics recorded in the control group. Adrenalectomy in rats was followed by a significant reduction of the nucleotide in all the structures, namely in the hypothalamus by 89.5%, and in the hippocamp and striate body by 30.3 and 30.5%, respectively. Application of substitution therapy (5 mg hydrocortisone per 100 mg body mass) prevented the decreased content of cAMP seen in the adrenalectomized rats, with its magnitude being within the limits recorded in the intact animals. Doca was little effective in this aspect.

Adrenal Cortex Hormones↗
PubMed1982

[Effect of experimental hyperinsulinemia on the insulin receptor activity of the plasma membranes of the fatty and liver tissue from rats with disturbed liver innervation].

A study was made of the effect of experimental hyperinsulinemia, caused by daily administration of the increasing doses of a crystalline insulin-zinc suspension (up to 6 Units per animal) during 14 days, on the parameters of 125I-insulin binding by the insulin receptors of plasma membranes of adipose and liver tissues of intact rats and those with disturbed liver innervation. In intact rats, hyperinsulinemia led to the fall of the concentration of the insulin receptors and their affinity for insulin in the membranes of both tissues. In rats with disturbed liver innervation, analogous changes were observed for the receptors of adipose tissue, whereas the parameters of the receptors of liver were unchanged under the effect of hyperinsulinemia. It is concluded that nerve fibers that innervate the liver take part in the regulation of activity of the insulin receptors.

Adipose Tissue↗
PubMed1981

[Establishment of the endocrine function of cultured beta cells of the islets of Langerhans].

Monolayer cultures of pancreatic islets obtained from the pancreas of guinea-pigs aged 10 days and 3-3.5-months pig embryos were studied at the 2d-3d, 5th-6th and 15th-16th days. These times corresponded with the stages of culture intense growth, stabilization and physiological dying off. The rate of insulin biosynthesis and secretory activity of beta-cells were evaluated from the intensity of 3H-uridine and 3H-leucine incorporation and from the magnitude of immunoreactive insulin secretion into the cultural medium. The proliferating and insulin-synthetizing beta-cells were detected by selective 3H-thymidine or 3H-leucine incorporation. In the stages of culture intense growth and dying off the viable beta-cells were distributed into insulin-synthesizing and proliferating ones. During the transition to the stabilization stage the proliferative level of beta-cells drastically decreased, while the biosynthesis and insulin secretion rates increased. This manifested in the increased number of beta-cells which intensely incorporated 3H-thymidine into the nucleus, and 3H-leucin into the cytoplasm, as well as in the rise of immunoreactive insulin concentration in the culture.

Animals↗
PubMed1980

[Cyclic adenosine-3',5'-monophosphate content in the limbic system structures of the rat brain on the administration of corticosteroids].

The effect of hydrocortisone and DOCA on the cAMP content in the hypothalamus, hippocampus and striate body of the rat brain was investigated. Single (determined after 1 and 24 hours) and repeated (7 days) hydrocortison administration in a dose of 5 mg/100 g body weight was accompanied by an increase in the cAMP concentration in the brain structures under study. Single administration of DOCA in a dose of 0.5 mg/100 g body weight did not produce any changes in the cAMP level in the structures of the rat brain limbic system; however, the dose of 2.5 mg raised the cAMP level. Prolonged administration of the hormone in the above doses dod not change the cAMP level in the brain structures. Only the hippocampus showed a 210% increase in the cAMP level during DOCA administration in a dose of 0.5 mg.

Animals↗
PubMed1978

[Effect of O,N'=dichlorodiphenyldichloroethane and pertan in vitro on glutathione reductase activity in the adrenals of dogs and guinea pigs].

Glutathione reductase is activated by o,p'-dichlorodiphenyldichlorethane (o,p'-DDD) and pertan added in a concentration of 312 micrometer to the homogenate and cytoplasmic fraction of the dog adrenals. At a concentration of 156 micrometer o,p'-DDD and pertan failed to influence the glutathione reductase activity of the dog adrenal glands. Added in vitro, o,p'-DDD and pertan activate glutatione reductase of the quinea pig adrenal glands. O,p'-DDD does not affect the glutathione reductase activity of the liver and kidney cytoplasmic fraction in dogs. This observation confirms the high specificity of o,p'-DDD action on the adrenal glands.

Adrenal Glands↗
PubMed1977

[Concentration of prostaglandins and cyclic adenosine-3',5'-monophosphate in the tissues of rats].

The content of prostaglandines (PG) and cyclic 3',5'-adenosine monphosphate (cAMP) was investigated in rat tissues by the radioisotopic method of competitive binding. Maximum quantities of both PG and cAMP were revealed in the same most actively functioning organs: the brain, incretory glands, small intestine. Fatty tissue showed minimum quantities of these substances. Results indicate a close functional relationship between the PG synthesis and adenylatecyclase activity in the body tissues.

Animals↗