Therapeutic effect of vegetable oils and ubiquinone-9 on radiation injuries

The comparison was made of the protective (the administration 3 h before irradiation with a dose of 7.3 Gy) and therapeutic (the administration immediately and later after exposure) effects of soya oil (150 mg/kg) and oil solution of ubiquinone-9 (100-200 mg/kg) on survival of exposed rats. It was shown that soya oil and ubiquinone-9 increased the survival rate of rats when administered before and, to a lesser extent, immediately after irradiation. Corn oil administered immediately after exposure increased the survival rate as well. DMF for the therapeutic effect of soya oil solution of ubiquinone-9 was 1.08.     

Radiomodifying properties of the synthetic analog of prostaglandin F2 alpha-estrofan

Estrofan (0.1 to 5 mg/kg) administered to rats and mice 5 min prior to gamma irradiation with doses of 8.5 to 9.5 Gy (LD90/30) increases the survival rate up to 30-40 per cent. The drug is ineffective when administered 30 and 60 min before irradiation.     

Effects of irradiation by the low-intensity electromagnetic field of the millimetric range on the Daphnia magna culture at various developmental stages

The influence of low-intensity electromagnetic irradiation and exposure to cadmium on survival and reproduction rates of daphnia in the process of their ontogenesis is investigated. The effects of the irradiation are clearly manifested in the toxicological experiments at coactions of the irradiation and cadmium and are weakly exhibited at action of the irradiation itself. At all stages of development, the irradiation does not influence the survival rate of daphnia. However, the irradiation increases their sensitivity to cadmium effects.     

Estimation of the contribution of the dose rate to the effect of whole body uniform irradiation with 1000 MeV protons

Some biochemical indices of peripheral blood and spleen and the survival rate of albino rats after whole-body uniform irradiation with 1000 MeV protons delivered in two ways have been studied. The data obtained indicate that the dose rate contributes to the biological effect of impulse proton radiation.     

The ability of peripheral blood lymphocytes to repair DNA and the survival of rats

Individual and group differences were revealed in the capacity of rat peripheral blood lymphocytes of DNA repair in response to the DNA damaging test-effect of irradiation in vitro. The survival rate of rats irradiated with a dose inducing 50-per cent death was in a definite relationship with the repair capacity of blood lymphocyte DNA in each animal individual prior to irradiation.     

The effects of gamma irradiation on the survival and development of Clonorchis sinensis metacercariae

The effects of gamma irradiation on the survival and development of C. sinensis metacercariae were studied to evaluate the feasibility of irradiation as a control measure for clonorchiasis. Pseudorasbora parva were collected at an endemic river of clonorchiasis and were used for irradiation of the fluke in three schemes. The first (Scheme 1) was irradiation of the isolated metacercariae from the fish followed by infection to experimental rats. The second (Scheme 2) was irradiation of the fish, and then the metacercariae were isolated and infected to rats. The third (Scheme 3) was irradiation on the rat livers after infection with normal metacercariae. Irradiation doses varied from 5 to 100 Gy for Schemes 1 and 2, and 10 to 25 Gy for Scheme 3. The rats were sacrificed 2 to 6 weeks after infection. In Scheme 1, the metacercariae irradiated at 50 Gy failed to survive in the rats after 2 or 6 weeks. However, 1 to 44% of the metacercariae irradiated at 5-30 Gy survived. The estimated LD50 of Scheme 1 was 16.5 Gy. The flukes irradiated in Scheme 2 survived better than those in Scheme 1. The average worm recovery rate in 50 Gy was 28%(7-39% individually). Increasing the dose up to 100 Gy brought a remarkably low survival rate of an average 1%(0-3% individually). The LD50 of Scheme 2 was 47.5 Gy. Worm recovery rates in the 10 Gy group of Scheme 3 were 21-39%, and those in the 25 Gy group were 2% and 34%. Although the metacercariae were irradiated, all of the recovered worms were morphologically normal.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sympathetic hyperfunction causes increased sensitivity of the autonomic nervous system to whole-body X irradiation

Although the etiology of radiation sickness is still unknown, disturbance of the autonomic nervous system is suggested to be a factor. This study was designed to compare the radiosensitivity of spontaneously hypertensive rats possessing sympathetic hyperfunction and control Wistar-Kyoto rats, and to analyze the effects of radiation on the autonomic nervous system in both strains. After a 7.5-Gy dose of whole-body X irradiation, the blood pressure decreased significantly at 8 h and 2 days in the spontaneously hypertensive rats, but not in the Wistar-Kyoto rats. Epinephrine levels in the adrenal gland of spontaneously hypertensive rats decreased at 4, 8 and 24 h, unlike the Wistar-Kyoto rats. Radiation evoked a stronger increase in norepinephrine in the jejunum and colon of spontaneously hypertensive rats than in Wistar-Kyoto rats. Acetylcholine levels in the jejunum of spontaneously hypertensive rats decreased, in contrast to the increase in Wistar-Kyoto rats within 24 h after irradiation. The survival rate of spontaneously hypertensive rats was lower than that of Wistar-Kyoto rats and weight loss, appetite loss and morphological changes in the jejunum were greater in spontaneously hypertensive rats than in Wistar-Kyoto rats after irradiation. These results indicated that X irradiation caused greater activities in autonomic nervous function and severe radiation injury in spontaneously hypertensive rats. Sympathetic hyperfunction may be associated with a higher sensitivity to radiation, including radiation injury and radiation sickness.     

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. The melanin of natural animal origin has the anti-radial effectiveness with the single irradiation increasing the number of alive newborn descendants in a litter and doubling their survival during the first 30 days after the birth. The melanin's effect is less expressed with the chronic irradiation.     

Effects of a perfluorochemical emulsion on the response of BA1112 rat rhabdomyosarcomas to continuous low-dose-rate irradiation

The effects of the combination of a perfluorochemical emulsion (Fluosol DA, 20%) and carbogen (95% O2, 5% CO2) on the response of BA1112 rat rhabdomyosarcomas to continuous low-dose-rate irradiation were examined. Tumors were irradiated locally in unrestrained, unanesthetized rats at a dose rate of 0.98 Gy/h, using a specially designed 241Am irradiator system. Cell survival was measured using a colony formation assay. The tumor cell survival curves were fitted to linear relationships of the form ln S = - alpha D, where alpha for air-breathing rats was 0.104 +/- 0.005 Gy-1, as compared to 0.137 +/- 0.009 Gy-1 for rats treated with Fluosol plus carbogen. The increase in the slope of the survival curve produced by the treatment with Fluosol and carbogen was highly significant with a P value of 0.0015. The radiosensitization factor for the combination of Fluosol/carbogen plus continuous low-dose-rate irradiation was 1.32 +/- 0.11. Slightly less radiosensitization was observed with continuous low-dose-rate irradiation than in previous experiments using acute high-dose-rate irradiation. The diminished sensitization with Fluosol/carbogen during continuous low-dose-rate irradiation probably reflects the intrinsically lower oxygen enhancement ratio (OER) of low-dose/low-dose-rate irradiation, reoxygenation of the tumors during the prolonged treatment times used for continuous low-dose-rate irradiation, and the decrease in the levels of circulating perfluorochemicals during the 30-h irradiations. More importantly, the significant level of radiosensitization observed in the experiments with continuous low-dose-rate irradiation suggests that hypoxic cells persist in BA1112 tumors during continuous low-dose-rate irradiations and that the response of these tumors to continuous low-dose-rate irradiation can be improved by adjunctive treatments which oxygenate these radioresistant hypoxic tumor cells.     

Enhanced body radioresistance resulting from the transfusion of autologous blood irradiated with low doses of ionizing radiation]

Preliminary administration of autogenic blood irradiated in vitro with ionizing radiation in small doses of 0.05, 0.3 or 0.5 Gy resulted in a pronounced increase in the radioresistance of mice [correction of rats] subsequently irradiated in a dose of 9 Gy. The optimum was autotransfusion of blood irradiated in a dose of 0.3 Gy a day or 10 days prior to the total irradiation which increased the survival rate of experimental animals to 80% while, in control groups, the survival rate was only 10%.     

大鼠胸部照射后支气管肺泡灌洗液成分和肺组织纤溶活力的变化

大鼠胸部照射γ射线２０Ｇｙ,照射后观察支气管肺泡灌洗液（ＢＡＬＦ）中蛋白质含量、细胞总数和分类及巨噬细胞存活率,肺指数及肺组织纤溶活力,并做了大体解剖和组织学检查。结果为：照射后２周开始ＢＡＬＦ中蛋白质含量、细胞总数和中性粒细胞即明显增多,照射后１——２个月持续处于高水平,高峰在１．５─２个月,照射后３─４个月有所下降,肺指数有相应变化;肺组织纤溶活力则相反,从照射后２周开始持续下降,至照射后２个月已降至最低,接近于零。形态学观察也见到有早期肺水肿和晚期肺萎缩等变化。由上结果可见,大鼠胸部照射后的早期主要为渗出性病变和纤溶活力的降低。文中讨论了照射后血管内皮细胞的损伤在放射性肺损伤发病中的作用。     

Effect of therapeutic administration of purine derivatives on the life span of irradiated animals

Purine derivatives, meradine and ethimizole, are shown to exert a therapeutic effect with respect to survival of rats exposed to 4 Gy radiation. Distinctions in the death rate between the exposed rats and rats treated with meradine and ethimizole are manifested 1 month following irradiation, i. e. at the time of clinical recovery of the exposed body. The preparations used at other te terms are uneffective. It is suggested that purine derivatives increase the regeneration and compensation of radiation lesions at the time of clinical recovery reducing an irreversible component of radiation damage.     

Recovery capacity of glial progenitors after in vivo fission-neutron or X irradiation: age dependence, fractionation and low-dose-rate irradiations

Previous experiments on the radiosensitivity of O-2A glial progenitors determined for single-dose fission-neutron and X irradiation showed log-linear survival curves, suggesting a lack of accumulation of recovery of sublethal damage. In the present study, we addressed this question and further characterized the radiobiological properties of these glial stem cells by investigating the recovery capacity of glial stem cells using either fractionated or protracted whole-body irradiation. Irradiations were performed on newborn, 2-week-old or 12-week-old rats. Fractionated irradiations (four fractions) were performed with 24-h intervals, followed by cell isolations 16- 24 h after the last irradiation. Single-dose irradiations were followed by cell isolation 16-24 h after irradiation or delayed cell isolation (4 days after irradiation) of the O-2A progenitor cells from either spinal cord (newborns) or optic nerve (2- and 12-week-old rats). Results for neonatal progenitor cell survival show effect ratios for both fractionated fission-neutron and X irradiation of the order of 1.8 when compared with single-dose irradiation. A similar ratio was found after single-dose irradiation combined with delayed plating. Comparable results were observed for juvenile and adult optic nerve progenitors, with effect ratios of the order of 1.2. The present investigation clearly shows that fractionated irradiation regimens using X rays or fission neutrons and CNS tissue from rats of various ages results in an increase in O-2A progenitor cell survival while repair is virtually absent. This recovery of the progenitor pool after irradiation can be observed at all ages but is greatest in the neonatal spinal cord and can probably be attributed to repopulation.     

Indirect effect of x-irradiation on embryonic development: utilization of high doses of maternal irradiation on the first day of gestation

Two hundred and eighteen female rats were utilized in this study to evaluate the indirect effect of maternal x-irradiation on embryonic development and survival. There were two control groups and ten experimental groups receiving 0, 60, 150, 275, or 400 R on the afternoon of the first day. The use of special shielding devices permitted irradiation of either the mother or the zygote. Several groups of pregnant rats were exposed to 150 R on the afternoon of the first day of gestation. Irradiation of the oviduct and the ova resulted in a 60 to 70% resorption of the implanted ova. Irradiation of the maternal organism while the oviduct was shielded did not increase the resorption rate above control levels. Thus, no indirect effect was demonstrated when the maternal organism received 150 R. When the maternal rats received 400 R and the ova were shielded, 25 % of the implanted embryos resorbed. This was apparently not due to leakage of irradiation around or through the special shielding. Thus, high doses of irradiation in the rat have a moderate indirect effect, but this indirect effect first becomes manifest when the dose of irradiation is above the LD,0 following direct irradiation of the ova. Neither maternal irradiation nor zygote irradiation on the first day of gestation results in an increase in gross congenital malformations or produces fetal growth retardation.     

Radioprotective action of natural carotene-containing preparations: research on karotinil in white rats

Evidence was obtained that beta-carotene injected to rats subcutaneously or per os two times, 4 h and 19 h, before irradiation reduced their death rate from acute affection. The effect was almost invariable with the drug administered either before or after irradiation. The radioprotective efficacy of beta-carotene was attributed to its ability to scavenge active oxygen forms.     

The dynamics of folliculogenesis in the ovary of the progeny of animals irradiated in embryogenesis and early postnatal life

The prolonged irradiation with 1.0 Gy dose in prenatal and early postnatal periods of development of rats leads to the disturbance in the rate of follicular growth, the reduction of their pool, mainly the pool of young forms of oocytes. Processes of degeneration and destruction occur and develop in the ovary of both the irradiated rats and their first progeny.     

The experimental evaluation of antiradiation effectiveness of beta-estradiol on survival rates and bone marrow hemopoiesis of X-ray irradiated mice

The study was aimed at evaluating the radioprotective effectiveness of beta-estradiol following its prophylactic administration in conditions of acute irradiation. Evaluation of the radioprotective efficiency was performed by studying the 30-day survival rate, life expectancy, the structure of irradiated mice death, the bone marrow hematopoiesis using the method of exogenous colony formation. The prophylactic use of beta-estradiol at doses of 20 and 40 mg/kg 5 days before irradiation has been established to protect the exposed mice against radiation death induced by X-rays at doses LD50-90/30, thus increasing their survival rate by 17-58%, and to favor the reduced expression of post radiation disorders of bone marrow hematopoiesis.     

Effect of indometofen on the survival and bone marrow hemopoiesis of mice exposed to acute external gamma- or X-ray irradiation

The purpose of the study is evaluation of radioprotective effectiveness of indometofen at its prophylactic administration in conditions of acute irradiation. Evaluation of radioprotective efficiency was performed by studying the 30-day survival rate, life expectancy, structure of deathly irradiated mice, and bone marrow hemopoiesis using methods of endogenous and exogenous colony formation. The prophylactic application of indometofen at doses 30 mg/kg for 5 days before irradiation has been observed to protect mice against radiation death induced by gamma or X-ray exposures at doses LD(50-70/30), increasing their survival rate by 16-44%, and reduce severity of post radiation disorders of bone marrow hemopoiesis.     

Modification of the radiation injury of hematopoiesis in rats using the gaseous hypoxic mixture GHM-10

In experiments on Wistar rats it was shown that gas hypoxic mixture containing O2 (10%) and N2 (90%) had a radioprotective action with regard to the survival rate for 30 days and to the haemopoietic system status. The application of gas hypoxic mixture reduced the postirradiation cytopenia in the blood and lowered the degree of the bone marrow depletion by the 3d day following irradiation; DMF was 1.25 as determined by total bone marrow cellularity.     

Treatment of radiation nephropathy with captopril.

Both experimental and clinical radiation nephropathy are typically progressive, evolving to kidney failure over weeks to months. Other late radiation injuries (spinal cord, lung) are also progressive and have no known specific antidote. Recent reports of the efficacy of captopril in modifying radiation injury of the lung prompted this trial of captopril in treating established radiation nephropathy. Six months after 15-27 Gy in 12 fractions bilateral renal irradiation, 72 rats with blood urea nitrogen > 4.1 mmol/liter were started on captopril (500 mg/liter) or no drug in the drinking water. Subsequent survival was significantly enhanced in rats receiving captopril as opposed to no drug (P = 0.0013), and the rate of rise of blood urea nitrogen was significantly diminished (P < 0.0001) in the animals on captopril. Urine protein excretion was also reduced from initially elevated levels in the rats on captopril compared to levels in rats given no drug. We conclude that captopril therapy preserves kidney function, reduces proteinuria, and enhances survival in experimental radiation nephropathy.