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PubMed1991

Effect of intravenous tuftsin administration on histamine concentration in tissues of rabbits and guinea-pigs.

The performed studies covered the effect of tuftsin, tetrapeptide stimulating many components of immunological reactions, to histamine concentration in lungs, kidneys, liver, duodenum as well as in the blood of rabbits and guinea-pigs. Tuftsin was given intravenously in a single injection (0.5 mg/kg), and for guinea-pigs also in one-hour infusion (1.0 mg/kg/h). The tissue designed for determining the histamine concentration by spectrofluorimetric method were taken 1 hour after introduction of the peptide. It has been found out that tuftsin changes the histamine concentration in tissues, lowering it in the lungs, and elevating it in the kidneys and liver. The changes in duodenum and blood were insignificant.

Animals↗
PubMed1991

The evidence on the possible interleukin-1 alpha tuftsin competition.

It was demonstrated by the experiments performed in vivo in mice (peripheral blood leukocyte number determination), and in vitro on mouse thymocytes (autologous rosette forming cell number determination) that tuftsin (Thr-Lys-Pro-Arg), a natural phagocytosis-stimulating factor, inhibits the action of interleukin 1 alpha. This effect is interpreted by us in the terms of structural correspondence between tuftsin and "retro-tuftsin"-like sequence 210-213 of the IL-1 alpha peptide chain. The analysis of tertiary structure shows that this sequence is localized in the exposed fragment of the IL-1 alpha molecule, probably responsible for the interaction with the receptor.

Amino Acid Sequence↗
PubMed1989

[The role of the brain monoaminergic systems in the effects of tuftsin and its analog on animal emotional behavior].

The effects of tuftsin and its analogue TP-1 (300 micrograms/kg) on the animal adaptive behaviour in emotionally different situations, the level of biogenic amines and their metabolites 10, 30 min., 2 and 6 hrs after injection of these substances were studies. The TP-1 induced an increase in the memory traces stability better than tuftsin in emotionally negative situation. A single injection of the peptides induced changes in NA, DA and their metabolites contents for 30 min. to 2 hrs. In contrast to tuftsin, the TP-1 activated the metabolism of 5-HT in the hypothalamus and caudal brainstem without changing the NA turnover. The data obtained suggests that a stronger psychotropic activity of the TP-1 seems to be caused by its obvious effect on biogenic amines and their metabolites level in the brain.

Adaptation, Physiological↗
PubMed1989

[Effect of tuftsin on the orientation-exploratory behavior of normal white rats and against a background of pharmacologically induced disorders of the brain biogenic amine system].

The application of "hole board" method showed that the endogenic immunostimulator tetrapeptide tuftsin injected intraperitoneally in dose 0.3 mg/kg has a short-time stimulating action on the orienting reaction of rats in 5 min, though in 24 hours it suppresses the registered behavioral indexes. The pharmacological analysis of the above studied phenomenon showed that catecholaminergic and especially dopaminergic brain systems played the leading role in tuftsin effect. Tuftsin can normalize animals' behaviour disturbed by the pharmacological agents, which slightly influence the functioning of the brain dopaminergic system.

Animals↗
PubMed1988

[The action of tuftsin on the reaction of macrophage-suppressor formation in vitro and in vivo].

A cell suspension consisting of nonadhering and adhering spleen cells in the ratio 30:1 was incubated in a 10(-4) M tuftsin's solution during 15-30 min. The addition of 10(7) cells incubated in tuftsin syngeneic recipients resulted in the suppression of the immune response of the latter to sheep red blood cells. It was noted that this effect may be induced by using adhering cells only of intact donors and only when incubated together with nonadhering cells. The addition of tuftsin one hour after transplantation of the nonadhering spleen cells resulted in the suppression of the immune response. It was proposed, that suppression effect released through generation of the macrophage-suppressors.

Animals↗
PubMed1986

[Expression of the gene for hybrid beta-lactamase pBR322 with C-terminal fragment containing tuftsin (Thr-Lys-Pro-Arg)].

A hybrid beta-lactamase gene with a synthetic tuftsin-coding DNA fragment inserted at the Pst I-site of pBR322 plasmid has been obtained and its expression has been studied. Radioactive amino acids have been used to show that in E. coli chi 925 minicells up to 30% of newly synthesized chimeric protein is secreted into periplasm providing the tuftsin transport. After hybrid protein cleavage with CNBr, tuftsin has been isolated using ion-exchange and thin-layer chromatography.

Amino Acid Sequence↗
PubMed1981

[Central effects of the tetrapeptide tuftsin].

Under systemic administration tuftsin produces a marked influence on behavior and emotional reactivity in rats: enhances motor (vertical) activity, perception of pain stimulation and related aggressiveness and residual excitation. Activating effect is accompanied by an aggravation of the acquisition of passive avoidance reaction during single reinforcement. In vitro experiments revealed a direct inhibitory effect of tuftsin on the reaction rate of brain tyrosine hydroxylase activity. In vivo there was shown an increase in hypothalamic and especially striatal tyrosine hydroxylase activity. The data obtained indicate direct relationships between tuftsin central effects and the changes in brain catecholaminergic processes participating in the regulation of emotional-motivational and motor reactions.

Aggression↗
PubMed1983

Receptor-mediated internalization of tuftsin by human polymorphonuclear leukocytes.

A high-performance liquid chromatography (HPLC) purified fluorescein-labeled analogue of tuftsin was prepared, which retains the full biological activity of the native molecule. Characterization of the derivatization site by amino acid analysis, N-terminal cleavage, and dansylation revealed a monofluorescinated derivative at the alpha-amino terminus. Binding of the fluorescent tuftsin to living polymorphonuclear leukocytes (PMN) was observed by means of video intensification microscopy. At 37 degrees C, diffuse membrane fluorescence was seen initially, followed by rapid aggregation and internalization. The latter was demonstrated by saltation of intracellular fluorescent aggregates. These processes are temperature-dependent and rely on specific binding to the tuftsin receptor.

Amino Acids↗
PubMedDate not supplied

Interaction on the antinociceptive effect between neurotensin and enkephalins or tuftsin.

The aim of this paper was to study the interaction between neurotensin and both enkephalins or its synthetic analogue D-Ala2-metenkephalinamide, or tuftsin, on the antinonciceptive effect of these peptides in mice after intracisternal injection. Antinociception was measured by the hot-plate method. It was shown that neurotensin antagonized evidently the antinociceptive effect of enkephalins and their analogue. On the contrary, neurotensin and tuftsin were agonists in induction of analgesia. It is concluded that neurotensin modulates in an opposite way the function of the enkephalinergic neurons and the central action of tuftsin.

Animals↗
PubMed1983

Inhibition by tuftsin of Rauscher virus leukemia development in mice.

The antitumor effect of tuftsin, the natural phagocytosis-stimulating peptide, on leukemia induced by Rauscher murine leukemia virus (R-MuLV) was studied in vivo in SWR inbred mice. Tuftsin was found capable of significantly increasing the survival of R-MuLV-infected mice. The peptide, when injected both ip and iv into mice, exerted its activity in a dose- and time-dependent manner. Optimal antitumor activity was achieved upon administration of 25 micrograms tuftsin 4 days before R-MuLV inoculation.

Animals↗
PubMed1980

[Excitatory effect of tuftsin tetrapeptide on the activity of white rats].

Studies on male white rats have shown that tuftsin (trelys-pro-arg) enhances the locomotion in animals as disclosed by a series of the behavioral tests. The effect is dose-dependent: a dose of 50 microgram/kg did not change any of the test parameters, while that of 150 microgram/kg induced a short-term elevation of locomotion measured with an "Animeks". Administration of tuftsin in a dose of 300 microgram/kg led to the enhancement of the animals' locomotion as measured with the "Animeks", to the increased "open field" running time and to the reduced latent period of the reaction during the training in a T-shaped maze. Also, this dose of the peptide relaxed the reactions associated with fear. It is assumed that the effects observed are consequent on the stimulant action of tuftsin on the body of white rats.

Animals↗
PubMed1982

[Comparative evaluation of the effect of tuftsin and its analogs on immunogenesis].

The immunomodulator effect of tuftsin (Thr-Lys-Pro-Arg) and some analogs has been demonstrated on mice. All the peptides administered during the inductive phase of immunogenesis increased the content of antibody-producing cells in the spleen. Tuftsin and D-Arg-tuftsin appeared to be the most effective. The peptides did not affect the immune response under other application schemes.

Animals↗
PubMedDate not supplied

[In vitro effect of tuftsin (L-prolyl-L-arginine) on the oxidative capacity of polymorphonuclear lymphocytes in small-for-gestational-age newborn infants].

Tuftsin has the function of activating cellular macrophages and polymorphonuclears (PMNs). This tetrapeptide is transported by the CH2 domain of the heavy chain between residues 289 and 292 of the gammaglobulin (IgG) molecule. The objective of this work is to determine the effect of synthetic tuftsin in its oxidative capacity of PMN cells of newborns of low birth weight for their gestational age having already been demonstrated that the phagocytic activity of these cells of macrophages and PMNs is diminished compared with the cells of newborns of normal birth weight according to gestational age. Results showed a stimulatory effect of the PMNs oxidative capacity with synthetic tuftsin by the increase of the nitrotetrazolium blue reduction, demonstrating that the low oxidative capacity of the cells of newborns of low birth weigh for gestational age does not correlate with an intrinsic cellular defect.

Fetal Blood↗
PubMed1996

[Serum tuftsin concentration as an indicator of postoperative splenic function after spleen-preserving surgery].

Serum tuftsin level was measured by reverse-phase high performance liquid chromatography in 40 cases. Compared with 10 normal controls, tuftsin level remained almost unchanged in 20 autotransplantation cases after splenic resection for traumatic rupture of the spleen, and in 10 partially splenectomy cases for splenomegaly hypersplenism. The level of tuftsin was lower than that of the normal controls though it was higher than that of total splenectomy cases.

Adolescent↗
PubMed1999

Hydration effects on the electrostatic potential around tuftsin.

The electrostatic potential and component dielectric constants from molecular dynamics (MD) trajectories of tuftsin, a tetrapeptide with the amino acid sequence Thr-Lys-Pro-Arg in water and in saline solution are presented. The results obtained from the analysis of the MD trajectories for the total electrostatic potential at points on a grid using the Ewald technique are compared with the solution to the Poisson-Boltzmann (PB) equation. The latter was solved using several sets of dielectric constant parameters. The effects of structural averaging on the PB results were also considered. Solute conformational mobility in simulations gives rise to an electrostatic potential map around the solute dominated by the solute monopole (or lowest order multipole). The detailed spatial variation of the electrostatic potential on the molecular surface brought about by the compounded effects of the distribution of water and ions close to the peptide, solvent mobility, and solute conformational mobility are not qualitatively reproducible from a reparametrization of the input solute and solvent dielectric constants to the PB equation for a single structure or for structurally averaged PB calculations. Nevertheless, by fitting the PB to the MD electrostatic potential surfaces with the dielectric constants as fitting parameters, we found that the values that give the best fit are the values calculated from the MD trajectories. Implications of using such field calculations on the design of tuftsin peptide analogues are discussed.

Computer Simulation↗
PubMed1980

In vivo immunomodulating properties of two synthetic agents: azimexon and tuftsin.

Mice were submitted to various immunologic tests at different times after a single intravenous (IV) injection of azimexon or tuftsin in order to determine the mode of action of these chemically defined immunomodulators. Azimexon, (BM 12,531) an aziridine derivative, potentiated antibody responses to both thymus-dependent (TNP-KLH) and thymus-independent (TNP-LPS) antigens and DTH reaction to oxazolone when injected at least 1 day before the antigen. It activated macrophages, rendering them cytostatic for tumor cells, but depressed ADCC activity of spleen cells directed against antibody-coated CRBC. Tuftsin, a basic tetrapeptide, potentiated antibody response to TNP-KLH when injected at least 3 days before the antigen. The response to TNP-LPS was stimulated on days 1 and 3, but was slightly depressed on day 7. It rendered macrophages highly cytostatic for tumor cells but, as observed with azimexon, the activation process required 7 days to develop. ADCC was enhanced throughout the period of observation.

Adjuvants, Immunologic↗
PubMed1990

The characteristics of purified HL60 tuftsin receptors.

The purification and characteristics of purified HL60 tuftsin receptors are described. Purification was accomplished by affinity chromatography similar to that described earlier, wherein a tuftsin analog Thr-Lys-Pro-Pro-Arg, is covalently linked at the N alpha group to a solid support. The receptor consists presumably of two subunits approximately 66 KDa and 57 KDa. The dissociation constant of the receptor complex is 4.7 X 10(-8) M with 5 X 10(4) receptors per cell. It can form oligomers with an Mr of about 560 KDa suggesting an octomeric structure, assuming the same number of each subunit is associated.

Chemical Precipitation↗
PubMed1981

Macrophage activation by tuftsin and muramyl-dipeptide.

Peritoneal macrophages from tuftsin or MDP-treated mice were tested for their cytostatic activity for tumor cell proliferation. Both substances are able to activate macrophages either after intravenous injection or after incubation in vitro with normal macrophages. But a stimulation as well as an inhibition of tumor cell growth can result from macrophage activation depending on the timing and dose injected. Restoration of the impaired cytostatic capacity of macrophages of mice observed with aging, is obtained by repeated administration of tuftsin. Normal and BCG-stimulated macrophages were examined for their regulatory activity on the proliferation of P815 tumor cells. Low density of macrophages per well determines a stimulation of target cell growth whether the macrophages are normal or activated. When the number of macrophages is increased, under conditions in which normal macrophages are not inhibitory. BCG-stimulated macrophages exert already a strong cytostatic activity. At high macrophage content it appears that normal macrophages can also display an inhibitory activity. Macrophage-tumor cell interactions are highly dependent on the concentration and the state of activation of macrophages.

Acetylmuramyl-Alanyl-Isoglutamine↗