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Biomedical subjects

M I Titov

Publications and source records attributed to M I Titov.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Effect of a stable analog of leu-enkephalin, dalargin, on the cell division of the corneal epithelium in white rats].

The effect of Leu-enkephalin analog--dalargin--on the corneal epithelium proliferation has been studied in white rats. 10 microliter dalargin per 1 kg body weight were administered intraperitoneally at 8 a.m. The mitotic index (MI), DNA synthesis cell index and label intensity (LI) were determined every 4 hours over a 24-hour period. The results obtained demonstrate that dalargin stimulates DNA synthesis in cells throughout the entire period of action. MI increased only 4, 8, 12 hours after dalargin administration. Mean daily DNA synthesis cell index and MI increased 2.1-fold and 3.1-fold, respectively after dalargin administration. It is suggested that dalargin activates the cell division processes by speeding up mitosis, shortening the premitotic period, accelerating the speed of the DNA synthesis and increasing cell proliferation pool.

Animals↗
PubMed1987

Effects of opioid peptides and naloxone on nervous tissue in culture.

It was shown that opioid peptides stimulate nervous tissue growth in culture in the rat, which manifests itself in augmented outgrowth of neurites from explants and in an increase in the number of glial and fibroblast-like cells in the growth zone. The effects of opioid peptides ([Leu]- and [Met]-enkephalins, beta- and gamma-endorphins and some synthetic analogues of [Leu]-enkephalin) on the growth of organotypic cultures of rat sympathetic and dorsal root ganglia and spinal cord were investigated. Neurite outgrowth, cell composition, and size of the growth zone as well as the dynamics of its formation were estimated. Changes in the survival of neurons in dorsal root ganglion cultures were determined. The experiments were performed with living cultures as well as with fixed preparations. In experiments with sympathetic ganglia, it was demonstrated that a significant growth-promoting effect is exerted by peptides taken at concentrations of 10(-8) M to 10(-14) M. Naloxone does not eliminate the effects of peptides, but stimulates the growth at 10(-5) M to 10(-7) M. Studies with spinal cord revealed that naloxone (10(-6) M) enhances the response to [Leu]-enkephalin (10(-9) M). The survival of dorsal root ganglion neurons under the influence of a [leu]-enkephalin analog (10(-9) M) exceeds control values by approximately two to four times. Thus, opioid peptides were shown to exert a strong growth-promoting effect on nervous tissue in culture. This effect is dual: in neurons the peptides stimulate the outgrowth of neurites and their survival, while in glial cells they change the rate of their migration and, probably, their proliferation. It is suggested that opioid peptides, besides their already established functions, may play a role in the development and regeneration of nervous tissue.

Animals↗
PubMed1987

[Blood flow in skin wound tissue and systemic hemodynamics as affected by a collagen-dalargin complex].

In has been demonstrated that a collagen-dalargin complex increases blood flow in the granulation tissue (microsphere technique) due to the formation of new capillaries and a decrease in the vascular resistance. Dalargin had no effect on the capillary blood flow in the unaffected tissues. It has been concluded that the wound healing effect of dalargin may be related to its involvement in angiogenesis regulation.

Animals↗
PubMed1987

[The synthetic peptide preparation dalargin in the treatment of peptic ulcer].

The paper is concerned with the results of clinical assessment of a new peptide drug dalargin in therapy of duodenal peptic ulcer. Assessment of the efficacy of dalargin was compared to that of tagamet and placebo using double "blind" control. A total of 180 males with exacerbation of duodenal ulcer were examined, of them 90 received dalargin only, 70 received tagamet and 20 persons participated in an experiment based on a method of double "blind" control. An average period of duodenal ulcer healing in the patients on dalargin therapy was 21.4 +/- 1.2 days, and by the 28th day complete cicatrization was observed in 87.5% of the patients. In tagamet therapy an average period of cicatrization was 23.7 +/- 1.8 days, by the 28th day ulcer healing was observed in 87.3%. With placebo ulcer healing by the 4th week was observed in 30% of the examinees, in dalargin therapy in 80%. A conclusion was made of high efficacy of dalargin for therapy of peptic ulcer.

Adolescent↗
PubMed1987

[Effect of opioid receptor ligands on cell division processes in the corneal epithelium of the white rat].

The effects of the application of synthetic leu-enkephalin analogue--dalargin and naloxone on DNA synthesis and cell division in corneal epithelium were studied with the drugs injected once or five times. The influence of one and five intraperitoneal injections of the drugs in question at a dose of 10 micrograms/kg body weight was also investigated. In both cases the opioid receptor ligands examined activated DNA synthesis with the following adequate increase in mitotic index.

Animals↗
PubMed1986

[Features of the action of opioid peptides and naloxone on the tissues of the central and peripheral nervous system during cultivation].

The effect of opioid peptides (leu-enkephalin, a synthetic analog of leu-enkephalin) and naloxone on the organotypic culture of rat spinal cord and dorsal root ganglia was studied. The explants' outgrowth and dorsal root ganglion neuron survival were studied. Peptides (10(-9) M-10(-10)M) and naloxone (10(-5) M-10(-6) M) were found to be able to stimulate fibre outgrowth from the explant, to increase the numbers of glia and fibroblast type cells in the ganglion growth zone. It is suggested that opioid peptides can be used as a source of nonspecific growth factor for nervous tissue of peripheral and central nerve system.

Animals↗
PubMed1985

[Effect of opioid peptides on nervous tissue in vitro].

The effect of opioid peptides (gamma- and beta-endorphins, met- and leu-enkephalin, and 5 synthetic analogs of leu-enkephalin) was studied on organotypic culture of rat dorsal root ganglia and sympathetic ganglia. All peptides, except for one synthetic analog, were able to stimulate fibre outgrowth from explant, increase the numbers of glia and fibroblasttypic cells in the growth zone. The effect was observed in the range from 10(-10) to 10(-14)M. It is suggested that opioid peptides can be used as a nonspecific growth factor for nervous tissue.

Animals↗
PubMed1985

[Specific binding of 3H-naloxone with isolated rat enterocytes].

Specific 3H-naloxone binding with isolated rat enterocytes has been demonstrated. This binding was selectively inhibited by different opiates and proved to be irreversible, temperature-dependent and sodium azide-sensitive. The presence of naloxone binding sites on enterocytes indicates a possible involvement of opiates in the regulation of enterocyte functions.

Animals↗
PubMed1985

[Mechanism of the antistressor effect of D-Ala(2)-Leu(5)-Arg(6)-enkephalin].

It has been shown that the stable analog of leu-enkephalin diminishes to a great extent the stress-induced changes in the blood content of ACTH, cortisol, hypophyseal-thyroid hormones, the CAMP level in the adrenal and thymic tissues of white rats. It is assumed that this circumstance may interfere with depletion of the adrenal cortex and suppression of the lymphoid-macrophagal system.

Adrenal Glands↗
PubMed1985

[Dalargin--a peptide preparation with cytoprotective action].

The role and possible clinical use of regulatory peptides, a new type of regulatory substances, is discussed. Special attention is paid to the opioid peptides and their analogues. The new drug dalargin has been developed on the basis of the endogenous opioid peptide leucine-encephalin. Its action has been studied using experimental models. It has been established that the optimal dose (10 micrograms/kg) of dalargin is effective in preventing ulceration in the cystamine duodenal ulcer rat model and the development of stomach erosive lesions in immobilization stress, reducing the degree of liver degeneration in CCl4 poisoning, etc. With an increase of the dose of dalargin the effect "escapes". Dalargin is primarily bound by delta-receptors, it produces no analgetic effect and does not enter the brain. Dalargin exhibits a pronounced cytoprotective and regeneratory action and may take an important place in treating the internal organ diseases.

Animals↗
PubMed1985

[Effect of enkephalins on the course of experimental izadrin-induced myocardial necrosis in the rabbit].

The effect of a synthetic analogue of encephalin was studied experimentally in 150 rabbits with neoepinephrine-induced myocardial necrosis to whom the drug was administered intravenously at the rate of 100 micrograms/kg, 1 and 6 hours later. Necrotic developments were assessed on the basis of MB CPK and LDH activity and myoglobin levels. Control animals received saline solutions or propranolol in equimolar doses. In encephalin-treated animals, enzyme activity and myoglobin values were significantly lower, an evidence of encephalins' favorable effect on the course of neoepinephrine-induced myocardial necrosis.

Animals↗
PubMed1985

[Enkephalins and the function of the sympathetic-adrenal system in acute myocardial ischemia].

It has been shown in experiments on albino rats that acute myocardial ischemia (AMI) produces a noticeable increase in excretion of adrenaline, noradrenaline, DOPA and dopamine with urine. Intraperitoneal injection of leu-enkephalin analogs (D-Ala2-Leu5-Arg6 and D-Ala2-D-Leu5-D-Arg6) to rats with AMI was accompanied by a noticeable prevention of activation of the sympathoadrenal system.

Adrenal Glands↗
PubMed1985

[Stimulating action of endorphins on the development of sympathetic ganglia in culture].

The effect of gamma-and beta-endorphins, leu- and met-enkephalins on the growth and differentiation of nervous tissue was studied in organotypic cultures of the sympathetic ganglia of newborn rats. The growth of explants in living cultures and preparations stained by the Holmes method was analyzed. It was established that endorphins are capable of stimulating the growth of neurites from the explant, of increasing the number of glial and fibroblastoid cells in the zone of the growth. The mean value of the maximal magnitude of the zone of the growth in normalcy was 464 +/- 136 micron, that on addition of leu- and met-enkephalins, gamma- and beta-endorphins 879 +/- 161, 900 +/- 160, 959 +/- 170, and 1056 +/- 137 microns. The growth effect induced by endorphins was demonstrated within a wide dose range--from 10(-7) to 10(-14) M. Naloxone did not inhibit the stimulant action of the peptides. It is suggested that opioid neuropeptides can be used as a source of nonspecific growth factors for nervous tissue.

Animals↗
PubMed1985

[Effect of enkephalins on metabolic indices in experimental myocardial infarct in rats].

An experimental study in rats demonstrated that myocardial infarction, induced by the ligation of the descending branch of the left coronary artery, led to marked metabolic disorders, such as increased lactate and glucose levels and decreased levels of blood calcium and magnesium and hepatic glycogen. A stable analogue of leu-enkephalin administered to the animals normalized metabolic parameters and improved the course of experimental myocardial infarction in rats.

Animals↗