[Change in systemic hemodynamics after acute administration of diazepam binding inhibitor (DBI) and after autoimmunization against DBI]. / Izmenenie sistemnoi gemodinamiki pri ostrom vvedenii ingibitora sviazyvaniia diazepama i pri autoimmunizatsii k nemu.

Endogenous peptide DBI inhibits the activity of HABA-ergic system and that is why can be a factor of arterial hypertension development. We investigated DBI influence on cardiac index (CI), arterial pressure (AP) and heart rate (HR) in rats. I.v. administration of DBI caused dose--dependent increase in CI, AP but HR did not change. High dose (150 mg/kg) caused a biphasic answer: hyperkinetic reaction reversed to cardiodepressive one. Long-term immunization against DBI led to decrease of AP and systemic vessel's resistance.

[Increase of seizure threshold and resistance to stress in rats after immunization against fragment of diazepam-binding inhibitor]. / Povyshenie sudorozhnogo poroga i ustoichivosti krys k stressu posle immunizatsii k fragmentu diazepam-sviazyvaiushchego ingibitora.

White rats were immunized against fragment of diazepam-binding inhibitor octadecaneuropeptide (ODN) with conjugate ODN bovine serum albumin. This rats have reduced reactions of fear and anxiety in stress model of "open field" and in conflict Vogel test; their pain sensitivity ("tail flick" test) was lowered. The number and intensity of generalized seizure reactions after injection of pentylenetetrazole were decreased. The results show that active immunization to endogenous ODN has stress--protective and anti-seizure effects.

[Effects of piracetam on pain sensitivity and levels of beta-endorphin in blood and cAMP in the cerebral cortex of rats]. / Vliianie piratsetama na bolevuiu chuvstvitel'nost', uroven' beta-éndorfina v krovi i tsAMF v kore golovnogo mozga krys.

It has been shown, that piracetam by i.p. injection (10, 100, 400 mg/kg) or by consumption with drinking water 10, 100, 1000 mg/kg/day during 12 days delays extinction of conditioned reflex of passive avoidance and dose-dependence elevates exploratory activity in "open field", pain sensitivity threshold reduces to 70-75%. Prolonged consumption of 1000 mg/kg/day piracetam results in 3-fold decrease of beta-endorphin concentration in plasma (p less than 0.01) and 100 mg/kg/day--in 35% increase of cAMP content in rat brain cortex.

[Immunosorption method of urokinase determination]. / Immunosorbtsionnyi metod opredeleniia urokinazy.

An immunosorption procedure is developed for quantitative estimation of plasminogen activator of the urokinase type in human blood serum. The procedure involved sorption of urokinase from blood serum using polyclonal antibodies to the enzyme as a sorbent at the first step of the assay. Concentration of the immunoreactive urokinase in a preparation correlated with the absorbed fraction of standard urokinase added into the sample at the second step after washing of the sorbent. The residual fibrinolytic activity of the standard dose was detected in fibrin-agar gel. Results of the assay were not altered in presence of high molecular (bovine blood serum, soy bean inhibitor of trypsin) and low molecular inhibitors of urokinase (benzamidine, arginine, epsilon-aminocapronic acid). Sensitivity of the assay constituted 0.05 IU/sample (2.5 IU/ml, 0.25 ng/sample) and might be increased by a decimal order after addition of plasminogen into fibrin-agar gel. Content of urokinase in blood serum of healthy men (21-48 years old) was equal to 166 +/- 8.9 IU/ml with individual variations from 107 to 260 IU/ml.

[Interaction of plasminogen activator of urokinase type with human serum]. / Vzaimodeistvie aktivatora plazminogena urokinaznogo tipa s syvorotkoi krovi cheloveka.

Effects of blood serum on u-PA (EC 3.4.21.31) fibrinolytic activity were studied. After incubation for one hour at 37 degrees of the enzyme with human blood serum (55-145 IU/ml of blood serum) the enzymatic activity was completely inhibited. At the same time, amido-lytic activity of u-PA, estimated with low molecular substance S2444 as a substrate, was maintained in presence of blood serum. Blood serum inhibitors did not exhibit the specific affinity to u-PA. Serine proteases (trypsin, chymotrypsin and plasmin) competed with u-PA at equimolar concentrations. These inhibitors were inactivated after blood serum preincubation with primary amines methylamine, ethylamine, putrescine, spermidine and spermine (0.1-10 mM). The u-PA-inhibitor complexes were not dissociated in presence of 2.5 mM sodium dodecylsulfate. Trypsin-albumin copolymer bound specifically the blood serum u-PA inhibitors and the fraction adsorbed was electrophoretically characterized as a protein with molecular mass of 185 kDa.

[Participation of endogenous opioid peptides in the pathogenesis of motion sickness]. / Ob uchastii éndogennykh opioidnykh peptidov v patogeneze bolezni dvizheniia.

Investigations were performed with 19 healthy male volunteers to specify a possible role of endogenous opioid peptides in the pathogenesis of motion sickness. For this purpose the test subjects were administered naloxone, a specific antagonist of opiates and opioids, before rotation and during rotation in a BU-4 armchair at a rate of 30 rpm. In addition, the content of beta-endorphin in blood plasma was measured. It was discovered that naloxone exerts both prophylactic and therapeutic effects as regards the simulated motion sickness. In this respect it was more efficacious than the reference drug scopolamine. After rotation there was a significant increase in the beta-endorphin content in the blood plasma of the test subjects. It is assumed that endogenous opioid peptides (in particular beta-endorphin) may be directly involved in the genesis of vestibulo-vegetative disorders in motion sickness.

[Thromboplastic activity of higher plant extracts]. / Izuchenie tromboplasticheskoi aktivnosti ekstraktov vysshikh rastenii.

Hemostatic properties of extracts isolated from the birch floscules and willow blossoms have been revealed. An agent of thromboplastic nature which is identical to thromboplasin of the rat brain according to its biochemical composition and procoagulative action has been found in these extracts. In contrast to brain thromboplastin thromboplastic activity of plant extracts does not possess the species specificity. After intravenous injection of the plant extracts a reaction similar to defence reaction of the anticoagulation system in response to thromboplastin infusion of the rat brain develops in rats.

[Opioid peptide content of the brain and blood of rats under immobilization stress]. / Soderzhanie opioidnykh peptidov v mozge i krovi krys pri immobilizatsionnom stresse.

A study was made of the influence of acute and repeated immobilization on the content of immunoreactive metenkephalin (ME), leu-enkephalin (LE) and beta-endorphine (beta-E) in different regions of rat brain and that of beta-E in rat blood. Acute immobilization for 30 min led to a decrease in the content of the enkephalins in the hypothalamus. Meanwhile 150-min immobilization caused a remarkable increase in the opioid concentration in the hypothalamus and of the enkephalins in the pituitary. At the same time the beta-E content in the pituitary dropped to 38% of the control (P less than 0.001), that in the blood was twice as increased (P less than 0.05). Repeated immobilization for 7 days abolished these changes in the hypothalamus and pituitraty. The next day following immobilization for 39 days the content of LE and beta-E in the hypothalamus, medulla oblongata, midbrain and blood plasma was noticeably lowered. However, after successive immobilization it rose to the control level. The data obtained are discussed in the light of the involvement of opiate systems in the realization of antinociceptive and emotional effects of stress.

[Effect of short-term hypokinesia on the response of the opioid system in the rat]. / Vliianie kratokovremennoi gipokinezii na reaktsiiu opioidnoi sistemy krys.

The content of methionine-enkephalin, leucine-enkephalin and beta-endorphine was measured in various brain compartments (hypophysis, hypothalamus, midbrain, medulla oblongata, striatum), adrenals and plasma of the rats exposed to single and repeated immobilization. The reaction of the opiate systems to immobilization was very distinct in the emotiogenic brain structures (hypothalamus and midbrain) and hypophysis. The content of opiate-like peptides varied as a function of the immobilization time, with the most distinct changes occurring at the 150th minute. After daily immobilization repeated 40 times adaptation to the chronic stress-effect developed.