[Psychophysiological development of two generations of female rats chronically exposed to gamma-irradiation during pregnancy in the total dose of 1 Gy and its modification by melanin].

The purpose of the work was to study the embryotoxic action of chronic gamma-irradiation of pregnant female rats (F0) during the first 10 days of pregnancy in the total dose of 1 Gy (mean dose rate of 5.31 mGy/hour) on psychophysiological development of posterity of the first (F1) and the second (F2) generations and its modification by natural pigment melanin (peroral 10 mg/kg once per day during the irradiation). 54 pregnant female Wistar rats were the objects of research were their 180 descendants of the first generation and about 400 descendants of the second generation of maternal and of paternal lines.

[Consequences for posterity of two generations of an irradiation pregnant from females rats Wistar in small doses during a bookmark of reproduction system of fetuses development of posterity of the second generation and it reproduction function].

With the purpose of study of consequences for development and reproduction functions of posterity of the second generation from females rats Wistar of a total unitary gamma-irradiation in dozes 0.25; 0.5 and 1 Gy (capacity of a doze 0.

[The influence of the exogenous melanin on the development of the second generation of the female Wistar rats exposed during the critical period of the pegnancy at the nonsterilizing doses of different rate means].

The purpose of this study was to estimate the radio-protective activity of melanin for the reproductive status of Wistar rats. Wistar rats were exposed in utero either to the single gamma-irradiation on the tenth day of embryogenesis with the dose of 1 Gy or to the chronic gamma-irradiation with the total dose of 1 Gy during the first 10 days of embryogenesis. Such things like the ability of the rats to conceive, the embryogeny and early postnatal ontogeny of rat's posterity were studied.

[The influence of exogenous melanin on the development of female Wistar rats' posterity of first generation exposed to low doses at different dose rates during embryogenesis].

To research a radio-protective effect of melanin on the reproductive system during its creation the development of first generation posterity (900 descendants) of 125 pubertal female Wistar rats was examined after the single gamma-irradiation with a dose of 1 Gy (mean dose rate of 0.03 mGy/h), which they have been exposed to on the day ten of pregnancy, and the chronic gamma-irradiation with a total dose of 1 Gy (mean dose rate of 5.31 mGy/h) which they have been being exposed to during the first 10 days of pregnancy.

[Reaction of posterity of two generations after exposure of pregnant Wistar rats to low dose irradiation during the period of fetus formation. Development of the first generation posterity].

Whole-body single exposure of female Wistar rats to 0.25, 0.5 and 1 Gy of gamma-rays (dose rate of 0.

[Increase of probability of cell loss in the endothelium of blood vessel capillaries in progeny of rats after a low-dose irradiation of one of the parents (electron microscopy study)].

The total gamma-irradiation of Wistar rats at a dose of 0.25 Gy as well as at higher doses (0.5, 2 and 4.

[Embryogenesis and early postnatal ontogenesis of posterity of two generations of female Wistar rats, depending on the time of their fertilization after low dose radiation exposure].

On the first day and 3-10 or 40-60 days after a single whole-body gamma-irradiation with doses of 0.25, 0.5 and 1 Gy, the pubertal female Wistar rats coupled with intact males.

[Genetic consequences of irradiation of one or both parents (results of experiments on Wistar rats) Exitus lethalis in Wistar rat's progeny after irradiation of one or both parents].

Examination of 2563 offsprings of Wistar rats after irradiation of one or both parents with doses of 0.25, 0.5, 1, 2, 3 and 4 Gy was carried out; the manifestation of lethal effects in the progeny of the first generation in ontogenesis was studied.

[The genetic sequelae of irradiation in mammals (a review of the literature)].

The problem of hereditary effects of mammal exposure to ionizing radiation has a 95-year history but to date, no simple final solution has been available. Many papers on this problem specify the dependence of the hereditary effects on dose rate, regime, physical nature of radiation exposure, type, line and age of mammals that were studied. Over many years it was studied mainly as an aspect of hereditary radiation effects in progeny of one irradiated and the second non-irradiated parents.

[State of the progeny of the 1st generation conceived at different times after low-dose irradiation of female rats].

The relation between the antenatal and early postnatal ontogenesis of the progeny and the degree of maturity of oocytes at the time of the whole single gamma-irradiation with doses of 0.25, 0.5 and 1 Gy was studied on 473 first pregnant Wistar rats and 1402 rats of the first generation.

[The methodological aspects of experimental modelling and of assessing the hereditary sequelae of the irradiation of one and both parents].

The paper summarises some methodological approaches which may be used in experimental modelling and study of hereditary radiation effects in mammals. These approaches are aimed to the elucidation of the possible specific character (aggravation) of radiation damage in the offspring determined by the participation of two exposed parents in conception. The main attention is drawn to the dependence of hereditary radiation effects yield on the stages of the cell cycle of the parent germ cells at the moment of exposure and to criteria of evaluation of radiation damage in the offspring during the ontogenetic development.

[The postnatal development of the progeny of males whose germ cells were irradiated at different stages of spermatogenesis].

Distinct genetic radiosensitivity of germinal cells of males irradiated during different stages of spermatogenesis with doses of 0.25-5.0 Gy leads to reduction in vital newborn rats number in the first generation progeny and to elevated postnatal mortality rate.

[The consequences for the first-generation progeny of Wistar rats of the irradiation of both parents with a background of mexamine use].

In experiments with Wistar rats it was shown that the efficiency of mexamine as radioprotector was substantially lower when sex cells of both parents (spermatozoids, spermatids, ovocytes) were irradiated with a dose of 2-4 Gy than after irradiation one parent only. It may be associated with the aggravation of effects in the posterity being conceived from gametes of both exposed parents.

[Radiation effects in ontogenesis of the progeny of one or both irradiated parents].

The purpose of the investigation is the study and comparative analysis of radiation effects observed in antenatal and early postnatal ontogenesis of first generation progeny when one or both parents have been irradiated in doses 2, 3, 4 Gy. It was shown that the effects for the posterity of both exposed parents were attributed mainly to a female if mature oocytes were exposed to radiation, or to a male if maturing oocytes were exposed. If both parents have been irradiated at the spermatid, spermatozoid or mature oocyte stages and got 4 Gy aggravated effects in progeny are observed.

[Features of ontogenesis of the progeny of both irradiated parents].

Acute gamma-irradiation with a dose of 4 Gy of germinal cells of both parents in postmeiotic stages of gametogenesis results in increase of ineffective copulation rate. Antenatal and postnatal ontogenesis of first generation progeny shows worse consequences as compared with only one parent germinal cell irradiation.

[Consequences for the intrauterine development of the offspring of the irradiation of male germinal cells at different stages of spermatogenesis].

Single whole-body exposure of adult male rats Wistar in different stages of spermatogenesis to gamma-rays (doses from 0.25 to 5.00 Gy) resulted in violations of antenatal development of the first generation offsprings.

[Neuro-autonomic mechanisms of the maintenance of blood oxygen balance in patients exposed to the effect of a gaseous hypoxic mixture].

The authors discuss the mechanisms of compensatory reactions of the human vegetative nervous system, its central and peripheral parts, in breathing a gaseous hypoxic mixture. Five types of neurovegetative reactions of the organism aimed at maintaining the oxygen balance in blood were distinguished. The interrelationship of values reflecting the activity of the central and peripheral parts of the vegetative nervous system in exposure to emergency effects is discussed.

[The effect of normobaric hypoxia on the functioning of links in the endocrine system].

The paper is concerned with the data on change in the blood level of ACTH, STH, TSH, cortisol, T3, insulin, C-peptide during a 25-minute session of respiration using a gaseous hypoxic mixture with 10% oxygen (GHM-10). The investigation was performed in 23 healthy volunteers. Change in the hormonal status, characteristic of a moderate stress-reaction, was observed in 60% of the examinees.

[Late sequelae of gamma irradiation of rat ovaries during embryonic development].

From abnormalities in the first pregnancy, antenatal and postnatal development of the Wistar rat offspring subjected to a single whole-body gamma irradiation (0.5-1.5 Gy) during embryogenesis, it was inferred that ovaries were most radiosensitive on days 10-16 of the antenatal ontogeny with regard to the remote effects of irradiation.

[Relation of postradiation superovulation to the development of embryos and progeny of Wistar rats].

In experiments with 470 primigravida Wistar rats and 2248 kid rats of the first generation a study was made of the relationship between the postirradiation superovulation and viability of embryos and offspring of females subjected to whole-body gamma-irradiation with doses of 1 to 4 Gy. The extent and durability of superovulation are a function of radiation dose while the superovulation itself is accompanied by an increased pre- or post-implantation death of embryos and a decreased postnatal survival of the offspring.

[Enhancement of the radioprotective action of gas-induced hypoxia by using dextran sulfate].

Mice of the strain (CBA X C57Bl) F1 injected with a single dose (40 mg.kg-1) of dextran sulphate (m.w.

[The use of mexamine to reduce radiation injuries during embryogenesis of Wistar rats].

In experiments with 330 Wistar rats experiencing their first pregnancy and 1430 neonatal rats of the first generation a study was made on the toxicity and radioprotective efficiency of a single subcutaneous injection of 10 mg/kg mexamine on days 3, 11 and 19 of pregnancy. The agent caused various abnormalities in pregnancy, delivery and postnatal development of the offspring of nonirradiated animals, and it was almost ineffective when used for the prevention of radiation damages during the antenatal ontogenesis.

[Effect of the gaseous hypoxic mixture GHM-10 on the radiosensitivity of the fetus and the development of offspring].

A gas hypoxic mixture containing 10 percent of O2 and 90 percent of N2 was shown to exert a radioprotective action on pregnant rats and young rats of the first generation if animals were exposed to ionizing radiation during the periods of preimplantation, organogenesis and fetus development. The effect depended on the radiation dose and the period of the intrauterine development of fetus.

Increased protective effect of hypoxia against radiation following activation of haemopoiesis with dextran sulphate.

The effect of pretreatment of mice with a single injection of dextran sulphate (DS) on the protective capacity of moderate hypoxia was analysed. Dextran sulphate activated haemopoietic stem cell populations, and irradiation under hypoxia one day after DS injection increased the number of haemopoietic stem cells surviving in the bone marrow of the femur, their recovery after irradiation, and the number of endogenous spleen colonies. A moderate hypoxia (15% O2 and 12% O2) significantly reduced the lethal effect of gamma rays in mice after DS injection and increased the value of LD 50/30.

[Effect of heparin on the antiradiation activity of cystamine, decreasing with a reduction in radiation intensity].

It was shown that a single injection of heparin (250 units/kg) 15 min and 24 h before irradiation potentiated a slight radioprotective effect of cystamine (dichlorohydrate, 170 mg/kg) which was registered after the administration thereof to mice 30 min before irradiation with an absolutely lethal dose at a dose rate of 0.0025 Gy/c.