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Background and Objectives : Mutual effect of the preliminary and therapeutic intranasal treatment of SD rats with DSIP (8 days) on the outcome of focal stroke, induced with intraluminal middle cerebral occlusion (MCAO), was investigated. Materials and Methods : The groups were the following: MCAO + vehicle, MCAO + DSIP, and SHAM-operated. DSIP or vehicle was applied nasally 60 (±15) minutes prior to the occlusion and for 7 days after reperfusion at dose 120 µg/kg. The battery of behavioral tests was performed on 1, 3, 7, 14, and 21 days after MCAO. Motor coordination and balance and bilateral asymmetry were tested. At the end of the study, animals were euthanized, and their brains were perfused, serial cryoslices were made, and infarction volume in them was calculated. Results : Although brain infarction in DSIP-treated animals was smaller than in vehicle-treated animals, the difference was not significant. However, motor performance in the rotarod test significantly recovered in DSIP-treated animals. Conclusions : Intranasal administration of DSIP in the course of 8 days leads to accelerated recovery of motor functions.

A structural analogue of the DSIP, peptide KND, previously showed higher detoxification efficacy upon administration of the cytotoxic drug cisplatin, compared to DSIP. DSIP and KND were investigated using the model of acute myocardial infarction in male SD rats and the model of acute focal stroke in C57Bl/6 mice. A significant decrease in the myocardial infarction area was registered in KND-treated animals relative to saline-treated control animals (19.1 ± 7.3% versus 42.1 ± 9.2%). The brain infarction volume was significantly lower in animals intranasally treated with KND compared to the control saline-treated animals (7.4 ± 3.5% versus 12.2 ± 5.6%). Injection of KND in the first minute of reperfusion in the models of myocardial infarction and cerebral stroke reduced infarction of these organs, indicating a pronounced cardioprotective and neuroprotective effect of KND and potentiality for the treatment of ischemia-reperfusion injuries after transient ischemic attacks on the heart and brain, when administered during the reperfusion period. A preliminary pilot study using the model of myocardial infarction with the administration of DSIP during occlusion, and the model of cerebral stroke with the administration of KND during occlusion, resulted in 100% mortality in animals. Thus, in the case of ischemia-reperfusion injuries of the myocardium and the brain, use of these peptides is only possible during reperfusion.

Subcutaneous injections of exogenous delta sleep-inducing peptide in a dose of 100 μg/kg (monthly, 5-day courses) to rats of various age groups (2-24 months) were followed by an increase in the expression of genes for SOD 1 (Sod1) and glutathione peroxidase 1 (Gpx1) in the brain and nucleated blood cells. The expression of these genes was shown to decrease during physiological aging of the body.

It is shown that subcutaneous injection of exogenous delta-sleep inducing peptide (DSIP) to rats aged 2-24 months in a dose of 100 μg/kg animal body weight by courses of 5 consecutive days per month has a stabilizing effect on the NADH-dehydrogenase activity in the mitochondrial fractions of various tissues, which together with increasing capacity of the antioxidant system should reduce the production of free radicals and their adverse action on cells macromolecule, herewith the activity of succinate dehydrogenase did not change.

It is shown that subcutaneous injection of exogenous delta-sleep inducing peptide (DSIP) to rats aged 2-24 months in a dose of 100 μg/kg animal body weight by courses of 5 consecutive days per month has a stabilizing effect on the state of lysosomal membranes in rat tissues (brain, heart muscle and liver) at different ontogenetic stages, and this effect is accompanied by increasing intensity of lysosomal proteolysis in these tissues.

16 DSIP analogues with substitutions of 1-2 amino acid residues were synthesized in order to investigate their potential use in medicine. Antioxidative properties of these peptides were studied in vitro and their detoxifying activity was examined in vivo on a model of toxicosis that was induced by the cisplatin cytostatic, which has been widely used in the cancer treatment. Practically all the studied DSIP analogues were shown to exhibit considerable direct antioxidative activity (AOA), and that of the ID-6 analogue was higher than AOA of DSIP and comparable with AOA of vitamin C and β-carotine. This analogue also demonstrated the most pronounced detoxifying effect towards cisplatin action, resulting in a decrease in the animal death from the acute cisplatin toxicity to 17% (in comparison with 50-67% for the control animals) and restoration of a number of cisplatin-sensitive biochemical blood parameters: decrease in the activity of aspartate aminotransferase and alanine aminotransferase and downregulation of the concentration of the final products of nitrogen exchange (creatinine and urea). Thus, the DSIP-relative peptides could be promising agents for the decrease in the toxic effects of cytostatics that are used in oncology.

It is shown that exogenous delta-sleep inducing peptide increases glutathione antioxidant system level in rat tissues at different stages of ontogenesis, by subcutaneous injection to rats 2-24 months postnatal development in a dose of 100 mg/kg animal body weight by courses of 5 consecutive days per month, and this effect is especially marked in non-renewable postmitotic tissues.

We have undertaken a comparative study on physiological activity of well known neuropeptide DSIP (WAGGDASG E) and new closely related peptide KND (WKGGNASGE) in vivo assays. The sequence of K2, N5-DSIP (KND) was found recently by the computer search for DSIP homologous sequences in available nucleotide and protein databases at 324-332 site of Lysine-specific demethylase 3 B (EC 1.14.11, Swiss-Prot: Q7LBC6.1, 1-1761aa). This human lysine-specific histone demethylase is a representative of the recently discovered family of so called JmjC-domain-containing histone demethylases encoded by JMJD1B gene and ubiquitously expressed in tissues of various mammalian species. Biological investigations performed in this work confirm our preliminary data that DSIP-related peptide KND exhibits the similar biological properties in comparison with DSIP. Assessed by us antioxidative, anticonvulsive and behavioral effects of KND were even more expressed than in DSIP case. These results provide the additional evidences to support our suggestion that KND can be a possible endogenous prototype of "real" DSIP.

Subcutaneous injection of delta-sleep inducing peptide (DSIP) to postnatal rats (aged from 2 to 24 months) during 5 consecutive days every months at a dose of 10 microg/100 g body weight favors normalization of the age-related changes in carbohydrate metabolism and shows hypoglycemic effect, as manifested by a decrease in the level of glycosylated hemoglobin in erythrocytes of test rats. The administration of DSIP in postnatal rats of different age also led to a decrease in serum total lipid level, total cholesterol level, and atherogenicity index and an increase in the level of high-density lipoprotein cholesterol.

Synthetic peptides corresponding to the 59-72 (I), 60-72 (II) and 61-72 (III) sequences of human interleukin 2 with their N(alpha) acetylated and C(alpha) methylated termini were shown to exhibit pronounced hepatoprotective properties. These peptides neutralized hepatotoxic effects of such agents as tetrachloromethane and galactosamine in experiments in vivo. The peptide action revealed as normalization of duration of the thiopental narcosis of experimental animals and the level of hepatospecific enzymes in their blood. The effects of peptides (I)-(III) proved to be similar to that of prednisolone (the well-known anti-inflammatory agent), whereas the bestatine cytotoxic dipeptide had no hepatoprotecting effect. The target of the hepatoprotective activity of the peptides was shown to be the preliminary activated macrophages. We proposed that this activity of the peptides was associated with their interaction with the a-subunit of the interleukin 2 receptor (IL-2Ralpha), because the X-Ray analysis pointed to this region as one of binding sites of IL-2 with IL-2Ralpha. Experiments on the influence of the most active (59-72)-peptide on growth of the IL-2 dependent cell line (CTLL) confirmed this proposal. The 3H-labeled peptide corresponding to the 59-72 sequence ofthe human IL-2 was shown to bind to the CTLL cels. We assumed that the binding of this peptide was specific and occurred precisely with IL-2Ra and virtually determined the binding constant. Its value (1.41 x 10(-6) M) was comparable with that of the interaction of IL-2 with IL-2Ralpha (approximately 10(-7) M).

Accumulation of oxidized proteins (evaluated by the levels of carbonyl and SH groups) in tissues of 2-24-month-old rats (spleen>myocardium>testicles>liver>skeletal muscles) has been demonstrated. Exogenous delta sleep-inducing peptide injected subcutaneously to rats of different age in a dose of 100 μg/kg by monthly 5-day courses protected proteins of the studied tissues from oxidation; its effect was tissue-specific. Delta sleep-inducing peptide exhibited a hypoglycemic effect: it prevented nonenzymatic glycosylation of hemoglobin and reduced the level of defective protein molecules during aging.

The authors show that exogenous delta-sleep inducing peptide (DSIP) injected subcutaneously to the rats in the age of 2-24 months of postnatal development in a dose of 100 mg/kg of animal body weight in courses for 5 consecutive days every month, has a hepatoprotective effect. DSIP does not affect the functional activity of the pancreas, and is not involved in the regulation of calcium homeostasis in the physiological aging of the organism.

Delta sleep inducing peptide (WAGGDASGE, DSIP) is a well known multifunctional regulatory peptide. Numerous studies have confirmed its stress-protective and adaptive activity which is independent of the origin or nature of the stress or other harmful factors. However, the biosynthetic origin of DSIP remains obscure, since nothing is known of its protein precursor(s) and their encoding gene(s). We have performed a comprehensive analysis of available gene and protein databases for homologous peptide sites within mammalian resources including man. A family of Jumonji C (JmjC)-domain-containing histone demethylases was shown to contain a sequence fragment closely homologous to DSIP. One type of these ubiquitous and phylogenetically ancient proteins encoded by JMJD1B gene includes the WKGGNASGE sequence that differs from DSIP by only 2 amino acid residues in positions 2 and 5. The respective peptide was synthesized and its biological effects were evaluated in a preliminary way in the forced swimming and antitoxic tests. We suggest that the histone demethylases of the JmjC-group containing DSIP-related region can be considered as possible protein precursors of endogenous peptides with DSIP-like activity., (Copyright © 2011 Elsevier Inc. All rights reserved.)

It is shown that the subcutaneous injection to the rats in the age from 2 to 24 months during 5 consecutive days every month with 10 microg/100 g body weight of delta-sleep inducing peptide (DSIP) suppresses lipid peroxidation preventing the increasing of malonic dialdehyde level in rats tissues and plasma, possesses a powerful antioxidant effect, which is realized by means of the activation of different endogenous antioxidant defense system of cell and extracellular fluid, including high- and low-molecular regulators of free radical processes. DSIP exerts stimulating influence upon the superoxid-dismutese, catalase, ceruloplasmin activities as well as the level of nonenzymatic antioxidants--urea and uric acids, because during organism aging the antioxidant defense systems are being suppressed. DSIP increases the volume of tissues and blood endogenous antioxidant defense system mainly by means of enzymatic antioxidant system, especially during later ontogenesis.

Female SHR mice received 5-days long monthly courses of delta-sleep inducing peptide (DSIP) preparation "Deltaran" subcutaneously in dose 5 mkg/kg during all their lives. It was demonstrated, that last 10% (most aged) of mice which received Deltaran lived for 16% longer than the controls. They had significantly higher amount of vertical activity in the "open field" test, than the controls, starting from time when they were 6 months old and until their natural death. Mice of Deltaran group spent 73% more time in the open arms of elevated plus maze, and 9 times more often explored the extremities of this maze, than controls. Also Deltaran slowed the spontaneous carcinogenesis parameters. It's assumed that DSIP preparation "Deltaran" have geroprotective, anxiolytic and antitumor activity.

For evaluation of the stress-protective influence of delta-sleep inducing peptide we studied its effects on the system of heat-shock proteins in immune cells using the method of flow cytometry. The peptide affected the expression of heat-shock protein 70 kDa in cultured human myeloleukemia K562 cells. Delta-sleep-inducing peptide reduces accumulation of intracellular heat shock proteins 70 kDa in cells cultured under conditions of high density.

A number of new inhibitors of plasmepsin II (PlmII) from Plasmodium falciparum, one of the key factors of malarial parasite survival, were synthesized. The inhibitors are analogues of pepstatin with various variants of Ala residue substitutions. Effects of the inhibitors on human PlmII and cathepsin D were studied. Inhibition of PlmII by the substrate was found, which required the use of the modified Henderson method for the determination of inhibition constants. Two synthesized inhibitors were shown to exhibit a pronounced selectivity to PlmII (K(i) = 5.5 and 5 nM) in comparison with cathepsin D (K(i) = 230 and 3000 nM, respectively).

The aims of the present work were to perform a comparative study of the effects of delta sleep-inducing peptide and Deltaran on neurons in emotiogenic brain structures and to address the question of whether it is possible to prevent or decrease the negative influences of stress loads on the severity of subsequent cerebral ischemia in rats, using glycine with delta sleep-inducing peptide combined in the neuroprotective formulation Deltaran. The results showed that Deltaran and delta sleep-inducing peptide had largely the same actions on the nature of spike activity of neurons in the dorsal hippocampus, paraventricular nucleus of the hypothalamus, and ventral anterior nuclei of the thalamus, evoking activation of some of the neurons in these brain structures. The dorsal hippocampus was dominated by activation of spike activity in response to administration of delta sleep-inducing peptide; Deltaran produced activation mainly in the paraventricular nuclei of the hypothalamus. In all animals given Deltaran, the index of brain blood supply was significantly greater than in animals not given Deltaran. The survival rate of cerebral ischemia was 100% in animals given Deltaran. Death occurred in 38% of animals not given Deltaran.

An aim of the present study was a comparative investigation of a delta-sleep inducing peptide and the drug deltaran on the neural activity of the brain structures involved in emotional processing. Another goal was to analyze the possibility to prevent negative effects of emotional stress on brain ischemia using, along with deltaran, glycine and a delta-sleep inducing peptide. Deltaran and the delta-sleep inducing peptide exert in general similar effect on the burst activity of neurons in the dorsal hippocampus, hypothalamic paraventricular nucleus and ventral anterior thalamic nucleus, inducing amplification of the majority of recorded units. The activation of neuronal activity was seen mostly after the delta-sleep inducing peptide microiontophoresis in the dorsal hippocampus and after the deltaran application in the hypothalamic paraventricular nuclei. The index characterizing blood supply was significantly higher in all rats receiving deltaran as compared to the controls. Animals receiving deltaran survived experimental brain ischemia in 100% cases versus 38% in those not exposed to this drug.

For evaluation of the nature of adaptogenic properties of delta sleep-inducing peptide we studied the effect of this substance on macromolecule biosynthesis in the brain of rats and mice exposed to burn injury and psychoemotional stress, respectively. Anabolic activity of delta sleep-inducing peptide depended on the purpose of adaptation corresponding to the type of stress.

The possibility of a correlation between the membrane properties of the delta sleep-inducing peptide (DSIP) and its analogues and their biological activity in vivo was examined by a comparative study of the membrane effects of these peptides. The peptides exhibiting biological activity in vivo were shown to cause a statistically reliable disordering of lipids in thrombocyte plasma membranes similar to the effect of DSIP. The membrane effect of the D-Val2, D-Tyr2, and Tyr1, Pro2 analogues of DSIP had the same bimodal dose dependence characteristic of natural DSIP. Only a slight nonspecific lipid disordering was registered for Trp-Asp-Ala-Ser-Gly-Glu, a biologically inactive hexapeptide analogue. These results indicate a correlation between the biological activity of the peptides during in vivo tests and their membrane properties in vitro. The structure-function relationship was studied within the group of DSIP analogues examined in vitro. The DSIP modeling effect, especially pronounced under the action of stress factors, was suggested to be directly associated with the ability of DSIP to change the dynamic structure of biological membranes.

Problem: Previous studies have shown that humoral, endogenous and somnogenic, delta sleep-inducing peptide (DSIP) has influence on insomnia, pain, adaptation to stress, epilepsy, etc. We investigated the potential of DSIP and its analogue DSIP-12 (a nonapeptide with alanine in position 2 of DSIP molecule substituted by beta-alanine) to antagonize metaphit (1-[1(3-isothiocyanatophenyl)-cyclohexyl]piperidine) induced generalized, reflex audiogenic seizures in adult male Wistar albino rats., Methods: The rats divided in four groups received (i.p.): saline; metaphit; metaphit+DSIP; and metaphit+DSIP-12, respectively. Metaphit-treated animals displaying seizure in eight previous tests received DSIP or DSIP-12 and afterwards audiogenic stimuli were applied at hourly intervals for the next 30 h. The animals were exposed to sound stimulation 60 min after metaphit administration and further on at hourly intervals. Incidence and severity of seizures were behaviorally analyzed. Selected EEGs and power spectra were recorded and analyzed., Results and Conclusions: Metaphit led to hypersynchronous epileptiform activity (polyspikes and spike-wave complexes) and increased power spectra 0.5-30 h after the treatment. Severity of metaphit seizures increased with time to reach the peak 7-12 h after injection. DSIP and DSIP-12 significantly (*P<0.05 and **P<0.01) increased in delta and theta frequency bands and decreased the incidence, mean seizure grade and duration of metaphit convulsions. The results suggest that DSIP and DSIP-12 may be considered as potential antiepileptics in the animal model, DSIP-12 being more efficient than DSIP.

A delta-sleep-inducing peptide in various concentrations inhibits the pharmacological activity of trypsin and pronase E under experimental conditions.

From the age of 3 months until their natural deaths, female Swiss-derived SHR mice were subcutaneously injected 5 consecutive days every month with 0.1 ml of normal saline (control) or with 2.5 microg/mouse (approximately 100 microg/kg) of delta-sleep inducing peptide (DSIP, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) as the preparation Deltaran solved in 0.1 ml of saline. There were 54 mice in each group. The results of this study show that the treatment with Deltaran did not influence food consumption, but decreased the body weight of mice; it slowed down the age-related switching-off of estrous function; it decreased by 22.6% the frequency of chromosome aberrations in bone marrow cells; it did not influence mean life span; and it increased by 17.1% life span of the last 10% of the survivors and by 24.1% maximum life span in comparison with the control group. We also found that treatment with Deltaran significantly decreased total spontaneous tumor incidence (by 2.6-fold), mainly mammary carcinomas and leukemias in mice as compared with the control group. This is the first report on geroprotector and anticarcinogenic effect of DSIP-containing preparation Deltaran.

Neuromodulatory delta sleep inducing peptide (DSIP) seems to be implicated in the attenuation of stress-induced pathological metabolic disturbances in various animal species and human beings. Mitochondria, as cell organelles, are considered especially sensitive to stress conditions. In this work, the influence of DSIP and Deltaran((R))-a recently developed product based upon DSIP-on processes of oxidative phosphorylation and ATP production in rat brain mitochondria and rat brain homogenates was studied. A polarographic measurement of oxygen consumption was applied to evaluate the impact of DSIP on maximal rates of mitochondrial respiration and coupling of respiration to ATP production. We provide evidence that DSIP affected the efficiency of oxidative phosphorylation on isolated rat brain mitochondria. This peptide significantly increased the rate of phosphorylated respiration V3, while the rate of uncoupled respiration V(DNP) remaining unchanged. It enhanced the respiratory control ratio RCR and the rate of ADP phosphorylation. DSIP and Deltaran exhibited the same action in rat brain homogenates. We also examined the influence of DSIP under hypoxia when mitochondrial respiratory activity is altered. In rats subjected to hypoxia, we detected a significant stress-mediated reduction of V3 and ADP/t values. Pretreatment of rats with DSIP at the dose of 120 microgram/kg (i.p.) prior to their subjection to hypoxia completely inhibited hypoxia-induced reduction of mitochondrial respiratory activity. The revealed capacity of DSIP to enhance the efficiency of oxidative phosphorylation found in vitro experiments could contribute to understanding pronounced stress protective and antioxidant action of this peptide in vivo.

In activity the comparative analysis of metabolic effects delta--sleep inducing peptide (DSIP) in tissues and erythrocytes of intact rats and under cold stress is conducted. The regulation effect of DSIP in attitude of free radical processes will be realised through modulation the prooxidant--antioxidant balance: both for intact animal, and at stress. Exogenous DSIP increases the antioxidant system activity in tissues of brain, liver and blood in standard conditions and under cold stress. The anti-stress effect of DSIP is directed as on increase of power endogenic enzymatic antioxidant system activity, specially glutathione peroxidase activity, and not enzymatic of antioxidant protection. The DSIP renders different influence on activity of prooxidant enzymes: for intact animal boosts the myeloperoxidase activity in blood neutrophils, not rendering essential influencing on the xanthine oxidase activity in tissues of brain, liver and activates the myeloperoxidase activity, depresses the xanthine oxidase activity for rats at stress. The membranotropic effect of DSIP in the norm and under stress is connected to increase of stability of protein--lipid interplays. The membranostabilizing effect of DSIP in conditions of stress is characterized decrease of polarity of lipid phase and negative surface charge of erythrocyte membranes, modified in course of lipid peroxidation.

The development of experimental acute pancreatitis (EOP) in rats is accompanied by (i) intensification of the lipid peroxidation (LPO) process and the accumulation of malonic dialdehyde (MDA, an LPO product) in the tissues of pancreas, liver, and kidney and in the blood serum, (ii) destabilization of membranes and reduction of the osmotic resistance of erythrocytes (ORE), (iii) increase in the concentration of extracorpuscular hemoglobin (ECH) and medium-molecular-weight molecules (MWM) in the blood serum, and intensification of protein autolysis in tissues. Preliminary triple intraperitoneal administration of a delta-sleep-inducing peptide (DSIP) in a dose of 12 micrograms/100 g body weight to the test rats with EOP stabilized LPO, improved the erythrocyte membrane structure, reduced the MDA level in tissues and blood serum, increased ORE, reduced the ECH and MWM level in the blood, and decreased the protein autolysis rate in tissues.

The three-dimensional structure of the Fab fragment of a monoclonal antibody (LNKB-2) to human interleukin-2 (IL-2) complexed with a synthetic antigenic nonapeptide, Ac-Lys-Pro-Leu-Glu-Glu-Val-Leu-Asn-Leu-OMe, has been determined at 3.0 A resolution. In the structure, four out of the six hypervariable loops of the Fab (complementarity determining regions [CDRs] L1, H1, H2, and H3) are involved in peptide association through hydrogen bonding, salt bridge formation, and hydrophobic interactions. The Tyr residues in the Fab antigen binding site play a major role in antigen-antibody recognition. The structures of the complexed and uncomplexed Fab were compared. In the antigen binding site the CDR-L1 loop of the antibody shows the largest structural changes upon peptide binding. The peptide adopts a mostly alpha-helical conformation similar to that in the epitope fragment 64-72 of the IL-2 antigen. The side chains of residues Leu 66, Val 69, and Leu 70, which are shielded internally in the IL-2 structure, are involved in interactions with the Fab in the complex studied. This indicates that antibody-antigen complexation involves a significant rearrangement of the epitope-containing region of the IL-2 with retention of the alpha-helical character of the epitope fragment.

An intraperitoneal injection of an exogenous delta-sleep inducing peptide (DSIP) at a dose of 12 microg/100 g body weight shifted the prooxidant-antioxidant balance of free radical process (FRP) in tissues and erythrocytes of rats: the activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the concentrations of antioxidants (reduced glutathione in particular) increased. The DSIP stimulated the myeloperoxidase activity in blood neutrophils and had no effect on the activity of xanthine oxidase, a prooxidant enzyme, in the brain and liver. Cold stress displaced the prooxidant-antioxidant balance by increasing the xanthine oxidase activity in tissues and decreasing the myeloperoxidase activity in blood neutrophils; it also inhibited the enzyme antioxidant activities in tissues and erythrocytes that was neutralized by an increased ceruloplasmin activity in blood plasma and by an elevated level of antioxidants in rat blood and tissues. Preliminary administration of DSIP to animals exposed to cold stress restored the prooxidant-antioxidant balance: it normalized the myeloperoxidase activity in blood neutrophils, decreased the xanthine oxidase activity, and increased the activity of antioxidant enzymes in tissues and erythrocytes restoring the antioxidant level. The molecular regulation mechanism of free radical processes by DSIP in tissues under stressful conditions is discussed.

Exogenous delta sleep-inducing peptide given i.p. to intact rats at a dose of 12 microg/100 g decreased the levels of diene conjugates and Schiff bases in liver and brain tissues and had no effect on xanthine oxidase activity in these tissues. Cold stress was accompanied by increases in xanthine oxidase activity in rat liver and brain, with a consequent accumulation of diene conjugates and Schiff bases, as compared with intact animals. Preliminary administration of delta sleep-inducing peptide before three days of cold stress led to decreases in xanthine oxidase activity and lipid peroxidation products in the liver and brain, as compared with values in stressed rats. The protective effect of delta sleep-inducing peptide in stress is discussed.

The synthetic peptide C-1-6 related to the central part of human interleukin 2 molecule (sequence 59-72; N- and C-modified) had been shown previously to inhibit cytotoxic activity of macrophages converting them to synthesis of growth factors. In this paper the effect of C-1-6 on growth of sarcoma 180 in mice was studied. C-1-6 significantly accelerated tumor growth having been injected into mice in dose 5 or 50 microg per animal since the 4th day after tumor cells transplantation. Supernatants of Mphi in vitro activated by C-1-6 (10 microg/ml) and injected into mice also accelerated significantly sarcoma mass diurnal increasing as compared to mice treated with supernatants of non-activated Mphi or activated with bacterial lipopolysaccharide. A single injection of C-1-6 into mice either at the day or at the next day of tumor cells inoculation increased significantly the number of vessels growing up to transplant, thus the forming of the vascular bed had preceded tumor volume enlargement.

I. p. administration of exogenous delta-sleep-inducing peptide (DSIP) decreased the amount of diene conjugates and Schiff bases in the liver and brain in rats. The xanthine oxidase activity, at that, did not change. Cold stress enhanced the xanthine oxidase activity well as the amount of diene conjugates and Schiff bases. Preliminary administration of the delta-sleep-inducing peptide to cold-exposed animals diminished the xanthine oxidase activity and lipid peroxidation in the liver and brain. Protective effects of the DSIP under stress is discussed.

Antioxidant system's state of erythrocytes and tissues in rats under normal and cold stress conditions was studied. Intraperitoneal injection of exogenic DSIP at the dose of 12 mkg/100 g body weight both, to intact and to cold-exposed animals results in the increase of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase activities and concentration of glutathione in red blood cells, liver and brain.

The effect of delta-sleep-inducing peptide (DSIP) on erythrocytic membranes of human donor blood was studied by the spin label and spin probe methods. The spin-labeled derivative of DSIP containing the N-terminal residue of 1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxylic acid was synthesized. An analysis of the ESR spectra of the spin-labeled DSIP derivative recorded after its incubation with a human erythrocyte suspension at 37 degrees C revealed a decrease in the rotational correlation time (tau c) and molecular order parameter (S) in comparison with the control solutions of the peptide in phosphate buffer (pH 7.4). The application of paramagnetic probes, 5-, 12-, and 16-doxylstearic acids and 3-doxylandrostanol, demonstrated that the introduction of DSIP in an erythrocytic suspension significantly increased the mobility of the hydrophobic area of the membrane bilayer both at a depth of 20-22 A and in the subsurface area (4-6 A). The dependence of these effects on the DSIP concentration was shown to have the form of a curve with well-defined extremes. The maximal disordering of membrane lipids was observed at peptide concentrations of 10(-9) and 10(-6) M. These results suggested that DSIP significantly affected the structure of plasmatic membranes in vitro by changing the physical state of their lipid components.

Antigen-binding fragments (Fab) of mouse monoclonal antibodies to human interleukin-2 were obtained in preparative quantities by a modified procedure. These Fab-fragments were shown to be homogeneous according to the isoelectric focusing method. Various monocrystals of these free Fab-fragments and their complexes with the antigenic peptide corresponding to the 59-72 sequence of interleukin-2 were obtained. These were shown to be suitable for X-ray and were preliminarily studied by X-ray.

Experiments on rats were carried out to study the effects of administration of delta-sleep-inducing peptide (DSIP) and its analogs (9-14) into the reticular part of the substantia nigra and ventral hippocampus on picrotoxin- and kainate-induced epileptic activity. Additionally, the uptake of [3H]tryptophan by brain structures was studied. Intranigral and intrahippocampal microinjections of peptide and its analogs were found to have anticonvulsant effects against both picrotoxin- and kainate-induced epileptic activity. Studies of the effects of DSIP and its structural analogs on the uptake of tryptophan by brain structures showed that peptides predominantly increased uptake of this amino acid. It is suggested that brain structures which modulate tryptophan uptake are largely responsible for the anticonvulsant actions of DSIP and its analogs. The results obtained here provide evidence that the serotoninergic system is not of key importance in mediating the anticonvulsant effects of DSIP and its analogs.

Duodenase, a serine protease from bovine duodenum mucosa, was located in endoplasmic reticulum, the Golgi secretory granules of epithelial cells and ducts of Brunner's glands by the A-gold immunocytochemical method. Duodenase exhibits trypsin-like and chymotrypsin-like specificities with a preference for substrates having lysine at the P1 and proline at the P2 positions. The kinetic constants for the hydrolysis of 21 potential duodenase substrates are reported. The best substrates were found to be alpha-N-tosylglycylprolyllysine 4-nitroanilide (k[cat]/Km of 35000 M[-1] s[-1]), alpha-N-succinylthreonylprolyllysine 4-nitroanilide (k[cat]/Km of 18000 M[-1] s[-1]) and alpha-N-serylprolyllysine 4-nitroanilide (k[cat]/Km of 2600 m[-1] s[-1]), all of which contain the P1-P3 sequence of the enteropeptidase zymogen/activation site. On the basis of its catalytic properties and sites of localization, duodenase has been postulated to be an activator of the enteropeptidase precursor. A tetradecapeptide (LVTQEVSPKIVGGS) having the P9-P5'sequence of the cleavage site of zymogen activation of bovine proenteropeptidase was synthesized, and kinetic parameters of its hydrolysis by duodenase were determined (Km of 87 microM; k[cat] of 1.4 s[-1]; k[cat]/Km of 16000 M[-1] s[-1]). Crystals of duodenase frozen in a stream of liquid nitrogen diffracted synchrotron X-rays to 0.2-nm resolution.

A seizure-protecting effect of the delta-sleep-inducing peptide (DSIP) and its analogues was revealed. An intensive sorption of H3 tryptophan occurred under the effect of the DSIP and its analogues. The data obtained suggests that the serotoninergic system plays no important part in the seizure-protecting effect.

The effects of the peptides TSKYR and DY isolated from the brain of hibernating ground squirrels on Ca2+ current were studied. TSKYR activated Ca2+ current in frog auricle fibers and in single cells from frog ventricle whereas DY blocked Ca2+ current in both preparations. In isolated rat and ground squirrel cardiocytes, TSKYR had no effect on Ca2+ current, and DY increased it. In brain slices of rat, DY blocked the activity of medial septal neurons. TSKYR increased activity of septal neurons at the initial phase, which was followed by decrease of neuronal activity.

The peptide C-I-6 is a modified fragment (sequence 59-72) of human interleukin-2 and stimulates regeneration of hepatic cells and tissues. Study of the possible embryotoxic and teratogenic properties of C-I-6 showed that in some cases it induces the following statistically significant changes: reduces the number of viable fetus, increases the occurrence of hydronephrosis and the number of external and internal hematomas, increases the weight and size of the embryo. It is concluded that intraperitoneal administration of C-I-6 causes a mild embryotoxic and teratogenic effect in rats.

Studies were carried out in rats on the effects of the administration of delta-sleep-inducing peptide (DSIP) and its analogs (1-4) into the reticular part of the substantia nigra on movement and convulsive activity. Intranigral microinjection of DSIP, and of DSIP-1 and DSIP-4, reduced horizontal and vertical movement activity as well as excursions to the center of the open field. DSIP, DSIP-2, and DSIP-3 had anticonvulsant effects, consisting of increases in the latent periods of the first convulsion and clonicotonic convulsions induced by picrotoxin, and reductions in the mean intensity of convulsions. It is suggested that changes in the structure of DSIP are accompanied by alterations in the strength of the effects of this peptide on horizontal and convulsive activity after dosage into the reticular part of the substantia nigra. The results indicating that these peptides have protective activity in experimental convulsive syndrome suggest that a relationship exists between DSIP-induced reductions in movement activity and the anticonvulsive efficacy of DSIP analogs when administered intranigrally, this being one of the components of the nigrodependent mechanisms of inhibition of convulsions.

The spatial structure of cyclo(-Gly-DSIP-), a physiologically active analog of the delta sleep-inducing peptide, was determined by computer modelling using 1H NMR data. An interesting feature of the spatial structure in DMSO was detected. One side of almost planar resulting conformation is formed by the side chains of the Asp5, Ser7 and Glu9 residues, the side chain of the Trp1 residue forming the other part of the outer surface. This feature may be associated with the functional properties of the peptide.