Thymus Polypeptide Preparation Tactivin Restores Learning and Memory in Thymectomied Rats.

We studied the effects of tactivin and splenic polypeptides on learning and memory of thymectomized animals. In 3-week rats, thymectomy blocked active avoidance conditioning. Injections of tactivin (0.5 mg/kg) during 1 month after surgery restored learning capacity; splenic polypeptides were ineffective.

[The influence of the thymus peptides on analgesia caused by acute and chronic immobilization].

OBJECTIVE: Our aim was to investigate the influence of thymic polypeptides on pain sensitivity and to analyze a possible role of the opioid system in the implementation of the analgesia caused by immobilization stress. METHODS: The study was performed on male Wistar rats at the Moscow state University named after M. V. Lomonosov. We studied effects of thymus peptides: thymuline (0.15 mg/kg), fraction 5 thymosin (0.25 microgram/kg) and cattle thymus extracted product (CTEP) (0.5 mg/kg) on pain sensitivity in rats using test "tail flick" without stress, with acute (3 h) and sub acute (12 h) immobilization stress. The comparison groups were animals treated with saline and spleen polypeptides. RESULTS: It is shown that preparations of thymus increase the threshold of pain sensitivity in the intact animals. Immobilization stress duration 3 and 12 h in thymus peptides treated rats caused a less pronounced increase in pain threshold than in the control groups (immobilization stress 3 h: CTEP--p = 0.025, thymuline--p = 0.022, fraction 5 thymosin--p = 0.033; immobilization stress 12 h: CTEP--p = 0.034, thymuline--p = 0.027, fraction 5 thymosin--p = 0.036). The opioid receptor blocker naloxone (1 mg/kg) did not completely block the stress-induced analgesia, indicating the presence of both opioid and non -opioid components in this state. In thymus peptides treated rats, opioid component was less pronounced than in the control groups (CTEP--p = 0.031, thymuline--p = 0.026, fraction 5 thymosin--p = 0.029). CONCLUSION: Pre-activation of the opioid system by the thymus polypeptides leads to an increase in the share of non-opioid component of the stress-induced analgesia and prevents the depletion of the opioid system in immobilization stress.

Stress-protective effect of thymic peptides.

Experiments on Wistar rats showed that thymic peptides produce a stress-protective effect that manifested in prevention of functional impairment of conditioned active avoidance response and a decrease in generalized motor activity typical of higher nervous activity failure. We concluded that thymic peptides significantly modulate integrative functions of the brain and produce a stress-protective effect.

[Neuropeptides, Cytokines and Thymus Peptides as Effectors of Interactions Between Thymus and Neuroendocrine System].

The review presents data on mutual influence of nervous system and thymus, realized through the neuroendocrine-immune interactions. The pres- ence of adrenergic and peptidergic nerves in thymus creates conditions for implementation of the effect of neuropeptides secreted by them. These neuropeptides induce activation of thymus cells receptors and influence on the main processes in thymus, including T-lymphocyte maturation, cytokine and hormones production. In turn, thymuspeptides and/or cytokines, controlled by them, enter the brain and exert influence on neuro- nalfunction, which creates the basis for changes of behavior and homeostasis maintenance in response to infection. Ageing and some infectious, autoimmune, neurodegenerative and cancer diseases are accompanied by distortion of interactions between thymus and central nervous system. Mechanisms of signaling pathways, which determine these interactions, are not revealed yet, and their understanding will promote the development of effective therapeutic strategies.

Purification of high-molecular-weight subfraction from porcine skin inhibiting proliferation of A431 human carcinoma epidermoid cells.

Subfraction with a molecular weight >250 kDa isolated from porcine skin and inhibiting the proliferation of A431 human carcinoma epidermoid cells was purified by DEAE 32 anion exchange chromatography with NaCl concentration step-gradient. The effects of the initial subfraction and fractions obtained by separation in DEAE 32 on the proliferation of A431 human carcinoma epidermoid cells were studied in vitro in two tests (MTT and fluorescent test). The more sensitive fluorescent test showed the highest inhibitory activity of fraction No. 2 released from the column at 0.15 M NaCl. One major protein component and a series of minor protein components were detected in this fraction by vertical PAAG-SDS electrophoresis.

[The impact of immunoactive drugs on passive avoidance response].

AIM: The objective of this project was to explore the influence of immunoactive drugs (tactivin, thymulin, and thymosin fraction 5) on the development of the passive avoidance conditioned reflex. MATERIALS AND METHODS: Two types of passive avoidance boxes were used--a regular two-chamber box and a modified three-chamber box, comprising a dark chamber in which rats were exposed to electrical shock, a safe dark chamber, and a light chamber in the center. RESULTS: The project has established that the memory trace persists longer under the influence of the immunoactive drugs in both models, which is consistent with the reference nootropic piracetam test results. Notably, the immunoactive drugs' mnemotropic effect was more pronounced in the modified three-chamber box than in the standard two-chamber box. Using the modified box helped to establish the influence of tactivin, thymulin, and thymosin fraction 5 on the spatial memory component. Immunotropic preparations from thymus caused the animals to select the safe chamber 24 hours later and in subsequent tests. CONCLUSION: The project's results indicate that the drugs tested do possess mnemotropic properties, so their range of clinical use can be broadened.

[Effect of tactivin on the behaviour and learning in rats].

The action of the immunocorrective agent tactivin on CNS functional activity was studied in an experiment using outbred white rats. The drug was shown to affect the animals' behaviour in an elevated cross-shaped maze including learning capacity and ability to overcome functional disorders of conditioned active avoidance response. The data obtained suggest anti-stress activity of tactivin.

Effect of tactivin on functional disturbances in avoidance reaction in rats.

Experiments on outbred albino rats showed that tactivin (thymic polypeptide preparation) reduced functional disturbances in active avoidance reaction induced by extra electric current exposure violating the established relationships between the stimuli, reaction, and its result. The preparation provided high level of avoidance reaction after its violation. New effects of immunocorrective agent tactivin were detected. It not only restored the disordered immunological parameters, but also exhibited a pronounced effect on the higher integrative functions of the brain and produced an antistress effect.

New properties of immunotropic preparation from porcine skin.

We studied new immunological and physicochemical properties of K-activin, immunotropic preparation from porcine skin isolated by the acetone method. The preparation restored the sensitivity of background rosette-forming cells in the spleen of thymectomized mice to the inhibitory effect of azathioprine in vivo and practically normalized serum thymic activity reduced in thymectomized mice. The molecular weight of proteins present in K-activin and previously detected by SDS-PAAG electrophoresis was determined by MALDI mass spectrometry

[Restoration by T-activin and its subfractions of splenocyte membrane structures in thymectomized animals]. / Vosstanovlenie taktivinom i ego subfraktsiiami struktury membran splenotsitov timéktomirovannykh zhivotnykh.

It was shown that thymectomy induces the injury of plasma membranes of mouse splenocytes. This membrane disorders completely inhibit T-cell response on Concanavalin. A. The incubation of splenocytes with Tactivin or injection of Tactivin or its subfractions to the animals restore the membrane structure and T-cell response.

[The use of T-activin for the prevention of congenital influenzal infection in mice and the correction of the immune deficiency]. / Ispol'zovanie T-aktivina dlia profilaktiki vrozhdennoi grippoznoi infektsii u myshei i korrektsii immunodefitsita.

Viremia accompanying influenza infection and the possibility of transplacental passage of the virus into the fetus make it expedient to develop measures for the prophylaxis of intrauterine infection of the fetus in case of influenza during pregnancy. The work presents the optimum scheme of administration of T-activin for prophylactic purposes to pregnant mice with acute influenza infection. Besides, the use of T-activin for immunocorrection in case of established congenital influenza infection in mice is proposed.