Modification of the process of resorption of alpha-emitting nuclides from the gastrointestinal tract depending upon the properties of administered compounds and the physiological state of rats

In experiments on rats a study was made of resorption from the gastrointestinal tract of simple salts, complex compounds and "biologically incorporated" forms of transuranium nuclides, the influence of age, pregnancy and chemically active substances (for instance, trivalent iron and ethyl alcohol) on this process.     

Key Molecular Mechanisms of Aging,Biomarkers, and Potential Interventions

Molecular Biology - The mechanisms of aging are described at the molecular, cell, tissue, and systemic levels. Primary age-dependent molecular lesions activate the cell stress response to...     

The role of reaper-dependent apoptosis in radiation-induced life-span alterations in Drosophila melanogaster

This is the result of studying on a problem of radio-induced ageing. From the point of view of radiation genetics it is perspective to investigate influence of low doze irradiation on individuals with the mutant phenotypes that allows to assume a role of separate genes and mechanisms controllable by them in determination of life span and ageing. The role of a reaper-dependent way of apoptosis regulation in the induced change of life span is shown. The assumption is put forward that apoptosis has the important role during ageing an animal organism.     

Pharmacological PI 3-kinase inhibitors induce radioprotective effect in Drosophila melanogaster imago

Phosphatidylinositol 3-kinase (PI3K) signaling cascade is involved in many cell processes that are required for radioresistance, including proliferation, survival, growth, metabolism, and death. At the whole organism level PI3K signaling cascade is involved in lifespan control. In this study the contribution of PI3-signaling cascade to radioresistance of Drosophila melanogaster imago was investigated. It is shown that pretreatment with Pl3-kinase specific inhibitor LY294002 (5, 100 micromol/l) and wortmannin (5 micromol/1) leads to increase of male and female survival after acute irradiation in dose of 30 Gy. The obtained results demonstrate that PI3K specific inhibition induces radioprotective effect on Drosophila melanogaster imago.     

The influence of low doze gamma-irradiation on life span of Drosophila mutants with defects of DNA damage sensation and repair

It was shown that life span of wild type strain Canton-S increased after low doze gamma-irradiation. It was revealed the decrease of life span after irradiation in Drosophila mutants with defects of DNA damage sensation and repair genes mei-9 and mei-41, both in homozygous and heterozygous lines. In mei-41 line males' lives longer than females in contrast to other lines.     

Life-span in generations of chronic irradiated Drosophila wild type isogenic and geterogenic strains

With the goal to study radioadaptation on life-span and observe the role in this phenomenon of genotype, we investigated the dynamics of life-span in 14 consistent generations after chronic gamma-irradiation in heterogenic (Canton-S) and isogenic (Oregon-R spa) Drosophila wild type strains. The gamma-source was 226Ra in dose 60 cGy per generation. The animals kept in standard conditions (25 degrees C and 12 h lighting). Was shown, that the dynamics of median life-span in wild type strains Canton-S and Oregon-R spa was different and the character of alterations depends on genetic heterogeneity. After chronic irradiation in generations in heterogenic line Canton-S since 5 generation cyclic life-span oscillations disappeared, values of median life-span leave on a plateau. Since the 8th generation the life-span values of irradiated populations exceeded all the control values. As a result of the irradiation practically in all generations in isogenic line Oregon-R spa occurs increasing of life-span with the comparing to non-irradiated control. This is possible due to the positive influence of radio-induced heterogeneity on the life-span of isogenic strain. Thus, chronic irradiation led to violation of natural cyclic dynamics of Drosophila life-span in heterogenic strain, discovered in the end 80-s' years by F. Lints and D. Ismaylov. Irradiation of isogenic strain led to increasing of life-span in all generations.     

Genetic aspects of the irradiation in small doses of laboratory lines and experimental populations Drosophila melanogaster

One of explanations of revealed effects of small doses of an irradiation is induced genetic instability on which background there is a realization of the various radiobiological reactions resulting as to stimulation, and significant oppression of the vital functions of a cell or an organism. In work the given estimations of consequences of an irradiation in small doses of mutant lines of the drosophila are submitted. Paramount value in definition of their size and an orientation of reaction of a genotype is supposed, that, have processes leaders to change of activity of mobile genetic elements and programmed destruction of a cell.     

Age Dynamics of Adult Fly Activity in Drosophila Strains with Apoptosis Deregulation after Larval Exposure to Chronic Irradiation

The relationship was studied between radiation-induced apoptosis in the nervous system of Drosophila larvae and the age dynamics in adult fly neuromuscular activity. The level of apoptosis in the neural ganglia of third-instar larvae from the wild-type strain increased 2.5 times after larval exposure to ionizing radiation (54 cGy). Irradiation of the strain with enhanced sensitivity to apoptosis induction, which carries a mutation in gene–inhibitor of apoptosis th (allele th ⁴), and the wild-type strain Berlin led to an increase in neuromuscular activity of adult flies throughout the experiment and, consequently, to reduced aging rate. Conversely, this effect was not observed in strains with reduced sensitivity to induction of apoptosis (with mutations in genes dArk and Dcp-1).