Comparison of Direct Counts and Conductometric Measurements on a Hematology Analyzer Abacus Junior 5 Vet Myelokaryocyte Content in the Red Bone Marrow of Mice.

We studied the possibility of conductometric measurement of myelokaryocyte content in the red bone marrow of mice using a hematological Abacus Junior 5 Vet analyzer (Diatron). Statistical, correlation, and regression analyses were performed to assess of the results of myelokaryocyte counting in the suspensions of mouse red bone marrow by a direct method in cytometers and by using Abacus Junior 5 Vet analyzer. It was shown that in both intact mice and animals with modelled red bone marrow hypoplasia, irrespectively of the state of hematopoiesis in representative samples, conductometric measurements of myelokaryocyte content on the Abacus analyzer with high confidence reproduced direct counting results (in different tests p=0.64-0.82, p=0.83-0.98). This indicates that myelokaryocyte counting on the Abacus Junior 5 Vet analyzer can be an acceptable alternative to counting chamber measurements in mouse samplings. However, the variability of single measurements with the Abacus Junior 5 Vet in red bone marrow suspensions is high (5%) and this has to be considered in small samples.

Experimental Study of the Efficacy of Sodium Deoxyribonucleate Used in Combination with Co-Transplantation of Mesenchymal and Hematopoietic Stem Cells after Exposure to γ-Radiation.

We studied the possibility of using sodium deoxyribonucleate (Derinat) for improving the efficiency of co-transplantation of mesenchymal (MSC) and hematopoietic stem cells (HSC) to female F1(CBA×C57BL/6) mice with bone marrow aplasia caused by exposure to γ-radiation. It was found that immunomodulator Derinat enhanced the effect of co-transplantation, in particular, triple post-irradiation administration of Derinat accelerated hematopoiesis recovery judging from the parameters of peripheral blood, total cellularity of the bone marrow and spleen, and animal survival. Single or double administration of Derinat prior to irradiation was ineffective. The optimal result was obtained when the following scheme was applied: MSC→HSC with an interval of 48 h starting during the first hours after irradiation and triple administration of Derinat (in 10-15 min, 3 and 7 days after irradiation) in a dose of 3 mg/mouse.

Effect of Rat Exposure to Moderate Pressure Oxygen Atmosphere on Resistance of Erythrocytes against Hemolysis.

Exposure of male Wistar rats to oxygen atmosphere at moderate pressure (1.10-1.15 atm) for 4 h resulted in significant, transient, and reversible decrease in hemolytic resistance of peripheral blood erythrocytes. In 2 days after oxygen exposure, the bone marrow released young erythrocytes with enhanced hemolytic resistance as a compensation for oxygen injury. These findings suggest that normobaric oxygen load can be viewed as a stress factor of moderate intensity.

Effects of Exposure of Animals to Oxygen Atmosphere at Low Pressure on Lipid Peroxidation and Antioxidant Defense.

Relatively short-term (2.5 or 5 h) exposure of Wistar rats to oxygen atmosphere at moderate pressure (1.10-1.15 atm) resulted in an increase in LPO level and reduction of antioxidant activity in the blood serum. An increase in malondialdehyde concentration 1 day after termination of the exposure was followed by a decrease in the inhibiting activity of free radical oxidation of liposomal phospholipids induced by Fe(II) ions (100 µm). Malondialdehyde concentration increased by 1.29 times already after 2.5-h exposure and did not changed when the duration of the exposure to oxygen atmosphere was prolonged to 5 h. These data confirm the necessity of using substances potentiating antioxidant defense of the body during exposure to normobaric oxygenation.

[Radioprotective Properties of NO-Synthase Inhibitor T1023: I. Indicators of Radioprotective Activity and Interaction with Other Radioprotectors].

The study of radioprotective activity of NO-synthase inhibitor, N-S-isothiourea derivative T1023 showed that this compound has a significant therapeutic range of radioprotective activity (5.5-6.0) and its optimal radioprotective dose is 1/4 LD16. The value of its Radiation Dose-Reduction Factor totaled 1.4-1.8. We have demonstrated a pronounced pharmacodynamic interaction of T1023 with some known radioprotectors. The character of the interaction was determined by its vasoactive properties. Combined use of T1023 and cystamine, which causes a decrease in vascular tone, was accompanied by a statistically significant weakening of the radioprotective effect. But, the combined use of T1023 with serotonergic and adrenergic radioprotectors having a pressor action caused a statistically significant increase in the radioprotective effect. Moreover, T1023 combined with such radioprotectors caused the synergistic radioprotective effect even when used at small doses that do not have any radioprotective effect alone. The findings suggest that NOS inhibitors can be effective radioprotectors and are able to create new opportunities for the development of safer radioprotective agents. The very same compound T1023, according to current criteria of pharmacological screening, is certainly promising for further investigations.

[Study of the influence of low-dose γ-irradiation on the functional state of peripheral blood erythrocytes of rats].

Low-intensity radiation at the absorbed dose of 4 µGy/min is a stressor of medium strength. In male Wistar rats, a pronounced and long-lasting response occurs in the system of red blood cells at the accumulated dose of 4.8 mGy. Functional deficiency of circulating cells was evaluated by the resistance of erythrocytes to acid lyse and the activity of the main antioxidant enzymes--superoxide dismutase (SOD) and catalase (CAT). The minimum "threshold" doses of radiation that cause systemic reactions occur in the range of units of miligrey.

[Effect of synthetic tripeptides on hemopoietic stem cells in norm and after gamma-irradiation].

Our work was aimed at researching into the influence of dipeptide (gamma-dGlu-dTrp) "Timodepressin" and this dipeptide-based tripeptides on the colony-forming ability of the irradiated in vitro bone marrow and hemopoietic stem cells of the normal organism. Also studied was the effect of various doses (1-1000 microg/kg) of one oftripeptides (dAla-gammadGlu-dTrp) on the output of exogenous splenic colonies in the case of its introduction 48 hours before irradiation. It is shown that the mode of influence of the preparations produced on the basis ofdipeptides dGlu-dTrp and gamma-dGlu-dTrp on the initial stages ofa hemopoiesis in the normal and irradiated organism depends on the nature of the additional amino-acid residue and its optical orientation.

[Experimental assessment of embryotoxic action of low intensity ionizing irradiation in different periods of intrauterine development].

The prolonged ionizing radiation exposure at the absorbed doze rate of 2.6 mGy/hour and the total accumulated doze of about 20 cGy during different periods of the intrauterine development caused disorders of a coordinated development of organs and the decrease of endurance in physical activity in the postnatal ontogenesis of the irradiated posterity. The results obtained are comparable to the consequences of irradiation exposure of the fetus at the accumulated doze of 125 cGy during all stages of pregnancy and give grounds for considering radiation exposure at the above-mentioned rate (20 cGy) as a biologically significant factor.

[Influence of peptide derivatives of diketopiperazines on hemopoietic stem cells of an intact organism and irradiated bone marrow cells in vitro].

We have performed structural and functional studies of the hemotropic activity for a number of novel 2,5-diketopiperazine peptidomimetic derivatives. We employed a mouse model of hemopoietic stem cells cloning in the spleen of lethally irradiated animals. Biologic activity of synthetic products was studied in two experimental models: 1) in vitro irradiated bone marrow SFU-S was used for studying the radio modifying activity; 2) the biological effect of peptidomimetics on the intact non-irradiated bone marrow was evaluated in vivo. Various ways of administration of the peptidomimetics studied were used in the in vivo experiments: intravenous, intraperitoneal or subcutaneous injections and oral administration in the dose range of 10-10000 microg/kg. As a result of our work, we have discovered 2,5-diketopiperazine peptidomimetic derivatives with the dual activity: stimulation of intact committed SFU-S and radiomodifying activity.

[Experimental study of the radioprotective action of melanin on the somatic development during irradiation in the antenatal period of ontogenesis].

Daily introduction per os of the exogenous melanin in a doze of weight of 10 mg/kg pregnant female rats Wistar eliminated the functional deficiency of somatic development revealed at posterity at chronic gamma-irradiation in a doze 1.00-1.25 Gy for all period of pregnancy. The irradiation or introduction melanin antenatal to a phase ontogenesis resulted in stimulation of the immune answer, which was determined at offspring on 3rd week after birth. On the basis of the received data it is concluded presence radioembryoprotective actions melanin in the relation embryotoxic effects of small dozes of ionizing radiation and its participation in regulation immunogenes.

[Experimental study of the neuroprotective properties of the melanin in embryos irradiated during antenatal development].

Daily introduction per os of the exogenous melanin in a doze of weight of 10 mg/kg pregnant female rats of line Wistar on a background continuous irradiations (dose rate of 2.6 mGy/h within 20 days of pregnancy) eliminated deficiency cognitive functions at posterity. On the basis of the received data it is concluded presence radioembryoprotective actions of melanin in the relation neuro embryotoxic effects of small dozes ionizing radiation. Taking into account small toxicity of melanin, the preparation can be perspective for practical application.

[Radiation-induced and embryotoxic effects in experimental hyperthyroidism]. / Eksperimental'no indutsirovannyi gipertireoz: ego radioembriotoksicheskoe deistvie.

The purpose of this article was investigation the development of the posterity rat (line Wistar) in the postnatal ontogenesis after combined and separate action of gamma-radiation (1.25 Gy at 20 days) and hyperthyroidism, provoked by toxic thyroid doses of 100 mg thyroidin per rat. It was shown that hyperthyroidism did not affect physical development of the irradiated posterity, but in a long-time period (7 month) it was revealed a decrease in ability to the training of posterity rats after the combined action of the factors.

[Effects of electromagnetic field of thermal intensity on the hypophysis-thyroid unit of the neuroendocrine system]. / Vliianie élektromagnitnykh polei teplovoi intensivnosti na gipofiz-tireoidnoe zveno neiroéndokrinnoi sistemy.

Acute 12-minute exposure of laboratory rats to microwaves with specific dose rate (SAR) of 30 W/kg that exceeded a basal metabolism caused a transient response of hyppophysis-thyroid system of compensatory-adaptive character. Prolonged exposure to microwaves of less intensity (SAR = 6 W/kg, which approximately corresponds to basic metabolic rate for these animals) caused insufficiency of the function of thyroid control in a form of primary hypothyroidis.

[Experimental assessment of the cardiovascular system functional state in rats after chronic gamma-irradiation in various absorbed doses]. / Eksperimental'naia otsenka funktsional'nogo sostoianiia serdechno-sosudistoi sistemy u krys posle khronicheskogo gamma-oblucheniia v raznykh pogloshchennykh dozakh.

Prolonged anthenatal gamma-irradiation of rats with total doses of 1.25; 1.9 and 2.5 Gy resulted in discoordination of cardiovascular system function. This study confirm our previous data on negative effect of chronic gamma-irradiation on forming and development of the functional systems in the anthenatally irradiated organism.

[Biological effects of the low-intensive laser of the near infra-red spectrum]. / Biologicheskie éffekty nizkointensivnogo lazernogo izlucheniia blizhnefrakrasnogo diapazona.

The immediate and the remote effects of the total one-time uniform irradiation with arsenid-hallium laser (wavelength 0.89 mu, pulse power 450 W, pulsed mode 80-3000 Hz) on the new-born Wistar rats have been examined. The complex of tests illustrated the biotropical effects of used laser regimes. The stimulating or braking of the animal's growth was observed in accodanse with the laser regime.

[Experimental assessment of adaptive possibilities after chronic prenatal exposure to gamma irradiation at various absorbed doses]. / Eksperimental'naia otsenka adaptivnykh vozmozhnostei organizma posle antenatal'nogo khronicheskogo deistviia gamma-izlucheniia v raznykh pogloshchennykh dozakh.

The purpose of the investigation is the study of dose-response relationship at the antenatal exposure of low level ionizing radiation (137Cs, 1.0-1.25; 1.7-1.9 and 2.3-2.5 Gy during 20 days). The decrease of body weight in pregnant females and antenatal embryonic mortality at the doses 2.3-2.5 Gy are revealed. Physical postnatal anomalies with decrease of the adaptation were estimated by the strength endurance after antenatal exposure of gamma-rays at the doses of 1.0-2.5 Gy.

[Effects of low doses of ionizing radiation and induced hypothyroidism on the course of pregnancy and the development of the offspring in rats]. / Vliianie malykh doz ioniziruiushchei radiatsii i indutsirovannogo gipotireoza na techenie beremennosti i razvitie potomstva u krys.

The purpose of the investigation is the study and analysis of combined influence of gamma-radiation (137Cs, 1.25 Gy during 20 days) and mercazolyl (20 mg/100 ml drinkable water) in utero on the physical developmental of the rats in the postnatal ontogenesis. It was shown, that antenatal separate influence both of gamma-radiation and mercazolyl induced the decrease of the strength endurance. The combined influence both of these factors induced essential decrease of the strength endurance.

[Conditioned reflex activity in rats after chronic antenatal gamma irradiation in association with mercazolyl]. / Uslovno-reflektornaia deiatel'nost' krys posle khronicheskogo antenatal'nogo gamma-oblucheniia v sochetanii s merkazolilom.

The purpose of investigation is the study of combined influence of gamma-radiation (137Cs, 1.25 Gy during 20 days) and mercazolyl (20 mg/100 ml drinkable water) in utero on the intellectual state of rats in the postnatal ontogenesis. It was shown, that antenatal separate influence both of gamma-radiation and mercazolyl induced the delay of intellectual development in 2 and 7 months age. The combined influence of these factors induced essential increase observed effect. There is a party of the conditioned reflex activity in 7 month age.