Combined Preconditioning Reduces the Negative Influence of Cerebral Ischemia on the Morphofunctional Condition of CNS.

We studied the influence of combined preconditioning (compound pQ-4 and moderate hypoxia) on morphometrical parameters of neuronal populations in hippocampal fields CA1 and CA3 in rats after bilateral ligation of the common carotid artery. Preconditioning produced a neuroprotective effect, improved survival of pyramidal neurons in the early and delayed periods of modeled ischemia, prevented the formation of necrotic and apoptotic neurons and hyperactivation of microglia, and protected endotheliocytes. The positive influence of preconditioning factors on the morphometric parameters of the brain under ischemic conditions agrees with the results of behavioral tests (open field and elevated plus maze) that demonstrated increased locomotor activity and exploratory behavior of animals.

Neuroprotective Effect of Antioxidants and Moderate Hypoxia as Combined Preconditioning in Cerebral Ischemia.

We studied combined effect of moderate hypoxia and compounds pQ-4, pQ-915, pQ-1032, and pQ-1104 on neurological deficit and survival of rats after bilateral ligation of common carotid arteries. Preconditioning including moderate hypoxia and treatment with compound pQ-4 produced a neuroprotective effect and increased animal survival during the early (by 51%) and late (by 33.5%) periods of modeled ischemia and reduced neurological deficit (by 50% and 41%, respectively). Moreover, this combination of preconditioning factors prevented postischemic excessive activation of free radical oxidation in brain hemispheres and blood serum.

Determination of superoxide dismutase and SOD-mimetic activities by a chemical system: Co2/H2O2/lucigenin.

The bright chemiluminescence has been observed in the system: Co(2+)/hydrogen peroxide/lucigenin. The chemiluminescence intensity was directly proportional to either cobalt, hydrogen peroxide, or lucigenin concentrations. A procedure of determination of superoxide dismutase (SOD) activity by the chemiluminescence method in the cobalt-hydrogen peroxide-lucigenin system at pH 8.5 is suggested. A linear dependence was established between a relative chemiluminescence intensity and SOD concentration in the range of SOD concentrations between 0 and 4.5 nM, c (1/2) = 0.8 nM. The determination of SOD activity was performed in several tissue samples (rat plasma, erythrocyte hemolysate, and liver mitochondria). A technique of tissue sample preparation with the use of thermal inactivation of interfering proteins at 60 °C was used. The method was successfully applied for comparison of the efficiency of SOD mimetics.

[Antihypoxant effect of zinc(II) bis(N-acetyl-L-cysteinato)sulfate octahydrate in acute normobaric hypoxia].

Using two models of the acute normobaric hypercapnic hypoxia (ANHH) and acute normobaric hypoxia without hypercapnia (ANWH), some parameters of the impulse activity of somatosensory cortex neurons were studied in experiments on cats. A new antihypoxant drug--aminothiol complex substance composed of zinc(II) and N-acetyl-L-cysteine (piQ-1104, 50 mg/kg)--was used for the brain protection. The substance studied showed a high antihypoxant activity in the brain neurons during all stages of both ANHH and AHWH. The average active survival time during hypoxic state was increased 2-2.5 times in comparison to the control group. The neuron activity dynamics under ANHH and AHWH conditions and after piQ-1104 injection was observed.

[Antiradical activity of complex copper compounds (II) on coumarin ligand base]. / Antiradikal'naia aktivnost' kompleksnykh soedinenii medi (II) na osnove kumarinovykh ligandov.

The antioxidant capacity of copper chelates with coumarins has been studied by the method of iron-induced chemiluminescence. All substrates studied were potent antioxidants, comparable to butylated hydroxytoluene. The mechanism of the antioxidant action of these copper-coumarin chelates was similar to that of Cu-Mn-superoxide dismutase, with a coumarin part of the complex being involved as a free radicals trap.

[The antiradical activity of coumarin reductones]. / Antiradikal'naia aktivnost' kumarinovykh reduktonov.

The antiradical activity of coumarine reductones was investigated by the method of inhibition of Fe2+ induced chemiluminescence of egg-yolk lipoproteins. All coumarines studied exhibited high antioxidant activity. The dependence of chemiluminescence intensity on the antioxidant concentration shows that coumarines reductions resemble their chemical analog--ascorbic acid rather than the lipid antioxidant butilated hydroxitoluene (ionol).

[Antiradical activity of 3-substituted coumarins and their effect on iron-dependent chemiluminescence]. / Antiradikal'naia aktivnost' 3-zameshchennykh kumarinov i ikh vliianie na zhelezozavisimuiu khemiliuminestsentsiiu.

The antioxidant capacity of 3-aminocoumarin, 3-oxycoumarin, 3-acetylaminocoumarin, and 3-coumarin carbonic acid has been investigated with chemiluminescence measurement and by the accumulation of TBA-active products. All coumarins were found to be antioxidants, with 3-oxy-, 3-amino- and 3-acetylamino coumarins being capable of amplifying chemiluminescence at early stages of the process.

[Chromatographic method of determining membrane epoxide hydrolase activity]. / Khromatograficheskii metod opredeleniia aktivnosti membrannoi époksidgidrolazy.

A new method for determination of the activity of epoxide hydrolase (EC 3.3.2.3), an enzyme of the 2nd phase of the system of drug metabolism, in rat liver microsomes was developed. 9,10-Epoxy-9,10-dihydrophenanthrene was used as a substrate. The quantitative determination of 9,10-dioxy-9,10-dihydrophenanthrene was performed according to the method of the internal standard by HPLC in aqueous a cetonitrile on octylsilica gel with fluorescent detection. 1-Naphthol was used as the internal standard. The method is simple and requires no preliminary extraction of the sample and preparation of the derivatives. It is highly sensitive and rapid: the time of the chromatographic analysis is not more than 3 minutes. The error does not exceed 5 per cent.