[Reversible inhibitory action of adenosine diphosphate ribose on isolated rat heart and rat heart in vivo]

Cardiotropic effects of endogenous regulator of intracellular ionic balance adenosine diphosphate ribose (ADP-ribose) was studied on isolated rat heart using standard retrograde perfusion and on rat heart in vivo by means of implanted arterial catheters. Parameters registered were heart rate, pressure developed in left ventricle of isolated heart and blood pressure of rats in vivo. It was shown that ADP-ribose exerted cardiotropic action on isolated rat heart and that its effects did not depend on effects of its metabolite AMP. In concentrations 10-70 microM ADP-ribose caused negative dose dependent chronotropic effect. Amplitude of contraction of isolated heart changed equivocally. In concentration 70 microM ADP-ribose in 50% of cases produced biphasic action: negative inotropic effect was preceded by positive inotropic effect. In other cases this concentration exerted negative inotropic effect. In concentration 10 microM only negative inotropic effect was observed. Contrary to ADP-ribose its metabolite AMP exerted only monophasic positive inotropic effect on isolated heart. The preparations studied differed in dynamics of cardiotropic action. In experiments in vivo ADP-ribose and AMP caused monophasic negative chronotropic and monophasic positive inotropic effects.

[ADP-ribose and cADP-ribose--endogenous regulators of cellular ionic balance. Cardiotropic effects of ADP-ribose]

Functions and possible mechanisms of action of adenosine diphosphate ribose (ADP-ribose) and its cyclic analogue--cycle-ADP-ribose (cADP-ribose)-- substances pretend to role of novel second messengers are reviewed. Possible mechanisms of ADP-ribose and cADP-ribose synthesis regulation and metabolism are analyzed. Prospective mechanisms of ADP-ribose and cADP-ribose transportation into the cell are described. ADP-ribose and cADP-ribose are considered as endogenous regulators of ionic balance (in particular regulators of calcium balance) in different tissues. Effects of ADP-ribose on isolated heart of frog and warm-blooded animal (rat), as well as on rat heart in vivo are discussed. The role of ionic channels and receptors, gated by ADP- and cADP-ribose in regulation of cardiomyocyte ionic balance in normal and pathological condition are analyzed. The possible role of purine receptors in ADP-ribose and cADP-ribose effects on heart are discussed.

[Effectiveness of ultrasmall doses of endogenous bioregulators and immunoactive compounds]

The data and hypotheses on the mechanisms of action of ultrasmall doses (USD) and ultralow concentrations (ULC) of endogenous bioregulators and immunoactive compounds (regulatory peptides, cytokines, etc.) are presented. The reliability of the published data on the effectiveness of USD and ULC within the concentration limits 10(-13) - 10(-24) M and lower is considered.

Natural and hybrid (“chimeric”) stable regulatory glyproline peptides

The present concept of relative instability of regulatory peptides (RPs) in organisms must be amended. The recently characterized family of glyprolines and some other prolyl-glycyl-proline (PGP)-containing oligopeptides show the stability quite comparable with those of major pharmacological preparations. The ability of glyprolines to pass gastro-enteric tract barriers opens ways to per-oral administration of this new group of drugs such as semax, selank and their fragments. The most interesting approach is the creation of hybrid ("chimeric") peptide drugs combining the unmodified representatives of various natural RPs that distinctly manifest their inherent physiological activities and cooperate with each other in stabilization of whole peptide in vivo. As the result, the activity of such peptides as semax and selank may have value in a vide variety of pathological processes.

[Functional continuum of the regulatory peptides enhancing anxiety. Search for the optimal complexes as a basis for developing inhibitory therapeutic agents]

Regulatory peptides (RP) take an active part in managing the majority of physiological processes. One of these functional applications is the monitoring of the anxiety level, of panic state. This work represents the presumptive analysis of literature data of 1960-2004 on the effects of regulatory peptides enhancing anxiety (RP-AT). This information database was used for researching the characteristics of organization and functionality of the system of anxiogenic RP. Taking into account the method of vector representation of RP effects, estimation of spectra of physiological effects that can go with each of RP-AT and their combination, was carried out. The most perspective RP complexes of anxiogenic profile for further experimental development of inhibitory therapeutic agents are proposed.

[Influence of isolated virion proteins of hepatitis A virus on the behavior of rats]

Influenza A virus M-proteins can cause depression in experimental animals 1 day after administration. HA and NA, on the contrary, activate motor activity in animals under the similar conditions. The effect of viral proteins is dose-dependent.

[Pharmacokinetics of glyprolines (PGP) upon intragastric administration]

The pharmacokinetics of glyprolines upon intragastric administration in rats was studied by monitoring the content of tritium-labeled PGP in the blood plasma and protein, in organs (for 5 h), and urine (for 8 h). The maximum radioactivity (2.25% of the introduced level) in the blood plasma was observed 15 min after administration of [3H]-PGP. Then, the radioactivity level gradually decreased, but even in 5 h it exceeded 1%. In contrast, the radioactivity of deposited protein gradually increased. The content of labeled PGP and its metabolites in organs was much lower than in the blood. The radioactivity 15 min after administration was as follows (%): intestine, 1.4; stomach, 0.1; liver, 0.09; brain, heart, and kidney, < 0.05; in 5 h, the radioactivity level was below 0.02% (except for intestine, where it was still greater than 0.1%). No labeled PGP or its metabolites were found in the urine during the 8-h period of observations. It is not excluded that glyprolines introduced with PGP are involved in the synthesis of new peptides and proteins, including collagen.

Prevention of thrombus formation with glyprolines on various models of prethrombotic state and thrombosis in rats

Peroral administration of peptide Pro-Gly-Pro to 10-11-month-old rats with modeled prethrombotic state normalized functions of the anticoagulation system and produced a potent antiplatelet effect. Peroral administration of Pro-Gly peptide before provocation of thrombin generation and thrombus formation prevented death of animals from thrombosis. Experiments on rats with venous thrombosis induced by stasis and administration of thrombin showed that pretreatment with Pro-Gly peptide decreased the weight of formed thrombi.

The effects of ante- and postnatal hypoxia on the central nervous system and their correction with peptide hormones

Ante- and postnatal hypoxia significantly worsened the postnatal development of animals. The posthypoxic behavioral model included hyperactivity and decreased learning ability, these being typical manifestations of attention deficit disorder. A peptide constellation prevented and significantly improved posthypoxic postnatal development and eliminated the majority of negative behavioral changes.

[Highly stable regulatory oligopeptides: experience and applications]

The most stable regulatory peptides (RP) including the new family of RP (glyprolines) and derivatives of hybrid peptide MEHFPGP are characterized. High ability of glyprolines to penetrate into the blood-stream through the gastrointestinal tract is demonstrated. Antiulcer, antithrombotic and antidiabetic activities of glyprolines were discovered in experiments on white rats. The activity of oligopeptides PGP, PG and GP is compared. Mechanisms of glycoprolines activities and feasibility of their administration with connective tissue food proteins are discussed. Thus, glyprolines are perspective drugs for treatment of gastric ulcer, correction of hemostasis and thrombosis suppression prepared for preclinical trial.

[Direct and prolonged effect of thyroliberin in ultra small doses on contractility of the white rat mesentery lymphatic vessels]

The prolonged effect of thyroliberin in ULD after single intramuscular injection on contractility of lymphatic vessels directly was investigated. The controlled group of animals received injection of 0.2 ml of physiological solution. The experimental group was injected by 0.2 ml of thyroliberin in concentrations of 10(-10) or 10(-16) mol/l (1 x 10(-4) and 1 x 10(-10) micrograms/kg of the body weight respectively). During the experiment the animals were grouped in the following way: 1) directly after the injection; 2) 3 hours later; 3) on the 1st day and then every day during 2 weeks. Lymphatic vessels reactivity of the experimental animals as well as controlled was studied by application of thyroliberin and noradrenalin (in concentrations of 1 x 10(-16) and 1 x 10(-6) mol/l respectively) directly on mesentery lymphatic vessels. The lymphatic vessels reaction in control group of animals on the noradrenalin and thyroliberin was the same during the period of observation. Thyroliberin stimulated contractility at concentration of 1 x 10(-16) mol/l. The reaction of experimental group was dramatically decreased to 10(-4) mol/l on the 1st and the 3rd day (in the case i.m. injected concentration 1 x 10(-10) mol/l) and to 10(-10) mol/l (in the case of i.m. injected concentration 10(-16) mol/l). The lymphatic vessels reactivity to exogenous thyroliberin gradually established at the 6-7th days till 12th day from the moment of thyroliberin injection. The mechanisms of the action of thyroliberin in ULD are discussed.

[Neuropeptide thyroliberin in ultra low doses--anticonvulsant defense of the brain]

Thyroliberin (TRH) promoting endogeneous antidepressive effect is the most general regulator of the central mechanisms and visceral functions (especially respiration). Our group pioneered in applying the anticonvulsant action of TRH after local intranasal application). This application of TRH in ultra-low doses contrast the method of systemic TRH administration in the large doses). In our experiments intranasal application of 10(-8), 10(-10) and 10(-12) mol/l TRH significantly inhibited the severe epileptic motor fits in rats induced by PTZ. EEG also confirms beneficent effect of TRH (TRH suppressed SWD in cortex, amygdala and hippocamp). In the experiment that follows compared effects of TRH (pyroGlu-His-Pro-NH2) and its metabolite dipeptide His-Pro (10(-10), 10(-8) mol/l). The experiments make more precise that only TRH but not His-Pro posses the anticonvulsant properties. There is a good believe that medical potentialities of TRH have not been exhausted and its new possibilities of its usage will be revealed in epileptology.

Metabolism of PGP peptide after administration via different routes

Main pathways of degradation of PGP peptide possessing antiulcer and antithrombotic activities were studied after its intraperitoneal, intragastric, and intraintestinal administration. In experiments on rabbits we showed by HPLC that unmodified PGP is released into the blood after administration by all three routes and is detected in the plasma over 3-5 h. PG dipeptide is a more stable PGP metabolite presumably determining (together with tripeptide) its pharmacological properties.

[Administration of the omega-3 polyunsaturated fatty acid drug eiferol decreases alcohol motivation in albino rats by elevating the level of antibodies to alcohol dehydrogenase]

The study experimentally assessed the approach proposed by the authors to lower alcohol motivation, which involves enhancement of a specific immunity at the stage of alcoholization when acetaldehydemodified ethanol exchange enzymes [alcohol dehydrogenase (ADH)] and acetaldehyde dehydrogenase may be expected to occur. Omega-3 polyunsaturated fatty acid (PUFA) drugs enhance the formation of autoantibodies to modified ADH and decrease the activity of ADH in the stomach and liver. At the same time, PUFA drugs can, under certain conditions, produce an anti-alcoholic activity and a positive effect on the psychoemotional status of animals after the ethanol deprivation period.

[New role of a highly-stable oligopeptides, neurotrophins, and immunomodulators in the regulatory continuum]

We propose new approach to classification of regulatory peptides and proteins. It is based on the complex of their properties: stability, affinity to receptors, existence of specialized percursors, protein-transporters etc. In particular we describe very stable factors such as new peptide family named glyprolines.

[Rules of interactions and functional continuum of neuropeptides (on the way to the common conception)]

The biological activity of neuropeptides (NP) is extremely wide and, moreover, there are thousands of peptides. Due to the pronounced multifunctionality of each peptide and to the overlapping reduplication of bioactivity spectra of each peptide, a functionally persistent aggregate (i.e. the functional continuum of NP) is formed. The method of vector representation of NP effects is outlined, which makes it possible to classify the multitude of NP according to functional characteristics, to reveal the evolutionary rules of development of the peptide system for regulation of biological parameters, and to indicate the constellations of regulatory peptides that are the most promising to be studied from the medical point of view.

Therapy of peptic ulcer with semax peptide

Experiments used is combination with traditional preparations (omeprasole, de-nol, and solcoseril), Semax peptide (Met-Glu-His-Phe-Pro-Gly-Pro) possessing nootropic and neuroprotective activity significantly promoted ulcer healing in patients with refractory peptic ulcers. On day 14 of treatment ulcer healing was observed in 89.5% patients receiving intranasal Semax (1% solution, 2-4 drops 3 times a day for 10 days) vs. 30.8% in the control group. Clinical studies of antiulcer activity of Semax in different combinations with usual antiulcer drugs are needed.

Functional continuum of regulatory peptides (RPs): vector model of RP-effects representation

During the past decades, bioactive (regulatory) peptides have been identified as the major players in the regulation of many important biological processes. Dozens of peptides have found their application as pharmaceutical agents, which further stimulated research in this field making it one of the most rapidly developing areas on the edge of biological science and medicine. However, the fast accumulation of enormous amounts of experimental data has revealed a great difficulty in their analysis and demanded the development of a systematic approach for generalization of the obtained information. We propose a new computer-based algorithm for studying biological activities of regulatory peptides and their groups based on their representation as vectors in n -dimensional functional space. Our method allows the rapid analysis of databases containing thousands of polyfunctional regulatory peptides with overlapping spectra of physiological activity. The described method permits to perform several types of correlations which, when applied to the large databases, could reveal new important information about the system of regulatory peptides. It can select the groups of peptides with similar physiological role (peptide constellations) and search for the optimal peptide combinations with predetermined spectrum of effects and minimal side effects for their further pharmacological application. It can also reveal the role of regulatory peptides in induction of chain physiological reactions.

[Effect of thyroliberin on contractility and electrical activity of isolated bovine lymphangions]

The role of regulatory peptides is the least explored part in the field of humoral regulation of lymphatics. In this paper we continue a systematic investigation of their effects on the lymphatic vessels of various animals. The effect of thyroliberin was studied on bovine mesenteric lymphatics. The isolated lymphatics contractility and smooth muscle cell electrical activity were investigated. Thyroliberin in ultra low concentrations (1 x 10(-13)-1 x 10(-18) M) exerts a considerable stimulating effect. The mechanism of the theroliberin ultra-low concentrations action and a possibility of the medical usage of the obtained results, are discussed.

[Prenatal hypoxic stress: physiological and biochemical consequences, correction by regulator peptides]

The review is devoted to the problem of prenatal hypoxia influence on central and vegetative nervous system, cardio-vascular and respiratory systems, cell metabolism. It is shown that perinatal hypoxia is often resulted in severe non-reversal functional disorders of postnatal development based on significant morphological changes. Regulatory peptide pretreatment is discussed as one of the methods for correction of pre- and postnatal hypoxic consequences.

[Multicomponent antithrombotic effect of the neuroprotective prolyl dipeptide GVS-111 and its major metabolite cyclo-L-prolylglycine]

The experiments in vivo showed that the new nootropic prolyl-containing GVS-111 produces an antithrombotic effect, influencing various stages of the blood coagulation process. GVS-111 exhibits anticoagulant and fibrinolytic properties and enhances fibrin destabilization by reducing the XIIIa factor activity. These effects are manifested upon both intraperitoneal (1 mg/kg) and peroral (10 mg/kg) administration of GVS-111 (in both cases, a single daily treatment over a period of 10 days). The same effects (anticoagulant, fibrinolytic, antifibrin-stabilizing) were observed in in vitro experiments with both GVS-111 (10(-3)-10(-6) M) and its main metabolite cyclo-L-prolylglycine (up to 10(-10) M). In addition, the latter metabolite exhibited an antiaggregant effect. The antithrombotic activity of GVS-111, together with previously established neuroprotector properties, low toxicity, and the absence of complications, makes this compound a promising antistroke drug.