RESUMEN
Correlative relations of the liver supernatant enzymatic activity of catalase (CAT) and glutathione-peroxidase (GP) with the velocities of oxygen consumption (VO2) and carbon dioxide exhalation (VCO2) were analyzed by the two- and three-dimensional linear and non-linear statistical methods in mice. It is shown that despite the close functions, CAT and GP, nevertheless, exhibit opposite correlative and regressive links with the gaseous exchange indices. As was found by the pairwise linear method, the activity correlation with VO2 was positive for CAT, but negative for GP. The opposite patterns of correlation were also apparent under the three-dimensional non-linear analysis.
Asunto(s)
Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , Hígado/enzimología , Consumo de Oxígeno/fisiología , Animales , Dióxido de Carbono/metabolismo , Interpretación Estadística de Datos , Hígado/metabolismo , Ratones , Ratones Endogámicos CBA , Oxígeno/metabolismoRESUMEN
Qualitative and quantitative differences in correlative and regressive links between superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase were assessed in the mice liver by two- and three-dimensional statistical methods. Paired linear correlation analysis indicated SOD-CAT tandem as the correlatively acting enzymatic pair. Three-dimensional analysis revealed uniform response surfaces which exhibited higher activities at disproportional values of the other two and lower activities at proportional activities of the other two enzymes. The direct effect of the enzymes on each other was positive [table: see text] while the effect of their product was always negative.
Asunto(s)
Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , Hígado/enzimología , Superóxido Dismutasa/metabolismo , Animales , Modelos Lineales , Ratones , Ratones Endogámicos CBARESUMEN
The long-term effects of the R-irradiation of D. melanogaster at the 1-hour egg stage with the dosages of 0.25, 0.50, 0.75, 1.0, 2.0 and 4.0 Gy were investigated. DNA samples were isolated from whole 5-6-days adult males. The aliquots of DNA were digested by S1-nuclease. Preimaginal stage lethality increased with irradiation dose increasing. At the same time, decrease in imaginal LS (life span) was observed after irradiation with the greatest dose (4 Gy) only. Moreover, hormesis by LS has revealed: in males irradiation with 0.25, 0.75 and 1 Gy increased the mean LS, and with 0.25 and 0.5 Gy caused the maximum LS; in females exposures with 0.25, 0.75 and 2 Gy increased the maximum LS. The densitometric assay of DNA electrophoregrams showed decrease by 39.2% of the part of high-molecular-weight DNA in control as a result of S1-nuclease action. Samples of DNA from the irradiated flies were more stable to enzyme action. The higher stability of DNA originated from the irradiated flies could be the result of reparation system activation. Ultrastructural changes induced at the egg stage by irradiation at the dose of 0.75 Gy testify the increased transcriptional activity of the brain cells.
Asunto(s)
Drosophila melanogaster/efectos de la radiación , Drosophila melanogaster/ultraestructura , Adaptación Fisiológica/efectos de la radiación , Animales , Encéfalo/ultraestructura , ADN/metabolismo , Desoxirribonucleasas/metabolismo , Relación Dosis-Respuesta en la Radiación , Femenino , Homeostasis/fisiología , Homeostasis/efectos de la radiación , Esperanza de Vida , Masculino , Oocitos/efectos de la radiación , Oocitos/ultraestructura , Dosis de Radiación , Fase S , Factores Sexuales , Transcripción GenéticaRESUMEN
Studies were made of the effects of various classes of lipoproteins (LP) from the blood of rabbits with experimental hypercholesterolemia and human subjects with pronounced atherosclerosis on the vascular tone of rat thoracic aorta specimens. In hypercholesterolemia, there was a considerable weakening of a vasodilatory action of atherogenic LP fractions--LDL and VLDL. A vasodilatory effect of HDLP was not changed. In subjects suffering from atherosclerosis vasodilatory effects of both atherogenic and antiatherogenic HDLP decreased significantly. The revealed changes were related to shifts in lipid and protein components of LP complexes manifesting in the development of dyslipoproteinemia and dysapoproteinemia. In atherosclerosis accompanied with more profound changes suppression of vasodilatory effects of LP is greater than in transient experimental hypercholesterolemia. Consequently, changes of lipid and apo composition of LP and weakening of their vasodilatory action play a considerable role in the vessel tone changes in atherogenic situation.
Asunto(s)
Apolipoproteínas/farmacología , Arteriosclerosis/sangre , Hipercolesterolemia/sangre , Lipoproteínas/farmacología , Vasoconstrictores/farmacología , Vasodilatadores/farmacología , Anciano , Animales , Aorta Torácica/efectos de los fármacos , Apolipoproteínas/sangre , Modelos Animales de Enfermedad , Humanos , Lipoproteínas/sangre , Persona de Mediana Edad , Conejos , Ratas , Ratas Wistar , Vasoconstrictores/sangre , Vasodilatadores/sangreRESUMEN
The flow cytofluorimetric method allowed to show that intact liver nucleus population of adult (6 months) rats consists of discrete ploidy classes (2c, 4c, 8c and 16c+), from which the diploid class was approximately a half of the total nuclei. Thirty days after the wholebody X-ray irradiation with a dose of 2 Gy, the percentage frequency of each nuclear class was statistically unchanged. However, the polyploidization level of the total nuclear population increased. Partial hepatectomy induces an entering into mitotic cycle (maximum S-phase; 22 h after operation) of the most of the hepatocyte nuclei in both irradiated and unirradiated animals. With that the relative number of nuclei in S-phase decreases in geometric progression according to increasing of ploidy class. In regenerating liver of irradiated rats in comparison with that of unirradiated ones, the greater part of nuclei enters into the mitotic cycle at the expense of di- and especially tetraploid nuclei.
Asunto(s)
Núcleo Celular/efectos de la radiación , Regeneración Hepática/efectos de la radiación , Hígado/efectos de la radiación , Animales , Núcleo Celular/genética , Núcleo Celular/ultraestructura , Replicación del ADN/efectos de la radiación , Femenino , Citometría de Flujo , Hepatectomía , Hígado/ultraestructura , Regeneración Hepática/genética , Ploidias , Ratas , Factores de TiempoRESUMEN
Transfer of human apoAI gene, within the molecular construction which provides its expression, to the liver of adult and aged rats resulted in the appearance of human protein in their blood, and was accompanied by changes in the content of high-density lipoproteins, as well as by the shifts in their protein and lipid composition. Administration of the human ApoAI gene was followed by changes of the vasoactive effects of HDL. Gene implantation is capable of enhancing the direct vasodilatory effects of HDL in old animals, being weakened by ageing, even against the background of normal age changes in the vascular wall tone.
Asunto(s)
Envejecimiento/metabolismo , Apolipoproteína A-I/fisiología , Apoproteínas/metabolismo , Lipoproteínas HDL/metabolismo , Vasoconstrictores/metabolismo , Animales , Apolipoproteína A-I/genética , Técnicas de Transferencia de Gen , Humanos , Masculino , Ratas , Ratas WistarAsunto(s)
Envejecimiento/fisiología , Apolipoproteína A-I/genética , Técnicas de Transferencia de Gen , Lipoproteínas HDL/fisiología , Vasodilatación/fisiología , Envejecimiento/sangre , Envejecimiento/genética , Animales , Aorta Torácica/fisiología , Apolipoproteína A-I/sangre , Apolipoproteína A-I/química , Humanos , Técnicas In Vitro , Lipoproteínas HDL/sangre , Lipoproteínas HDL/química , Lipoproteínas HDL/genética , Músculo Liso Vascular/fisiología , Ratas , Ratas Wistar , Vasodilatación/genéticaRESUMEN
Experiments on adult and old rats have shown that blood lipoproteins (LP) exert a dilatatory effect on isolated-segments of the thoracic aorta in animals of different age. In old versus adult animals, the sensitivity of vessels in all LP fractions (LDL, VLDL and HDL (low, very low and high density LP)) was lower as a result of age changes in the reactivity of vessels. The capacity of HDL to produce a vasodilatory effect decrease with age, which may be linked to changes in the lipid and apolipoprotein composition. The results revealed a decrease in the level of phospholipids and an increase in the amount of total cholesterol in HDL observed in old age. The capacities of LDL and VLDL to exert a vascular dilatatory action remained unchanged with age.
Asunto(s)
Envejecimiento/fisiología , Aorta/efectos de los fármacos , Vasos Sanguíneos/efectos de los fármacos , Lipoproteínas/sangre , Lipoproteínas/farmacología , Envejecimiento/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Masculino , Norepinefrina/farmacología , Ratas , Ratas WistarRESUMEN
A comparative biochemical study of the structural-functional peculiarities of genetic apparatus and the content of lipid peroxidation products in the liver nuclei and mitochondria of adult (4.5-5.5 months) and old (22-24 months) CBA mice was carried out. The age-related changes were found as follows: relative content of transcriptionally active and matrix-bound chromatin fractions was decreased, and that of transcriptionally low active fraction was increased; the value of protein/DNA was increased only in transcriptionally active fraction; the value of mitochondrial genome expression coefficient was diminished due to a decreased content of proteins encoded by mtDNA; the concentrations of Schiff bases were elevated both in the nuclei and mitochondria. Possible mechanisms of lipid peroxidation involvement in the above mentioned changes of the nuclear and mitochondrial genetic apparatus are discussed.
Asunto(s)
Envejecimiento/genética , Núcleo Celular/genética , Peroxidación de Lípido/fisiología , Mitocondrias Hepáticas/genética , Animales , Cromatina/genética , ADN Mitocondrial/genética , Masculino , Ratones , Ratones Endogámicos CBA , Relación Estructura-ActividadRESUMEN
We have used young (2-3 months), adult (6-8 months) and old (26-28 months) rats. Nuclear DNA (nDNA) was isolated from the liver nuclei and chromatin fractions (RCh, repressed chromatin; ACh, transcriptionally active chromatin; MCh, membrane-bound chromatin) and thereafter loaded on nitrocellulose filters. Hybridization was carried out with radioactively labelled mitochondrial DNA (mtDNA) as a probe mtDNA was first isolated from the liver mitochondria of adult rats and then labelled in nick-translation reaction with 32P-dCTP. Radioautography densitometry data have shown that the content of mtDNA-homologous sequences in the liver nDNA was decreased in adult rats (56%) and increased in the old ones (240%), as compared with the young animals. mtDNA-homologous sequences were localized in the young rats mainly in the RCh, while the adult and old rats had similar sequences in the ACh. We suggest that the age-related dynamics of mtDNA-homologous sequences was due to various factors. At the early stages cell differentiation proceeds rapidly and is accompanied by structural and functional reorganization of both nuclear and mitochondrial genomes. These changes increase the probability of contacts and integration of mtDNA fragments and whole molecules in the nuclear genome. As a result, an elevated level of mtDNA-homologous sequences is observed in the liver nuclear genome of young rats. In adult rats, repair and elimination of cells with defective nDNA and decreased proliferation of hepatocytes account for decreased amounts of mtDNA-homologous sequences in nDNA. In old animals, the repair to destruction ratio shifts towards destruction and, hence, mtDNA-homologous sequences are accumulated in the liver nDNA. Age related dynamics of mtDNA-homologous sequences in the liver chromatin fractions is characterized by accumulation of these sequences in ACh and MCh chromatin fractions during maturation and ageing. This also confirms our suggestion that integration of mtDNA-homologous sequences in the nuclear genome is due to various mechanisms operational at the early and late stages of ontogenesis.
Asunto(s)
Envejecimiento/metabolismo , Cromatina/metabolismo , ADN Mitocondrial/metabolismo , ADN/metabolismo , Hígado/metabolismo , Homología de Secuencia de Ácido Nucleico , Envejecimiento/genética , Animales , Autorradiografía , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/aislamiento & purificación , ADN/genética , ADN Mitocondrial/genética , ADN Mitocondrial/aislamiento & purificación , Femenino , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , RatasRESUMEN
Three fractions of chromatin were obtained from nuclei of the regenerating rat liver: transcriptionally low active (TLA), transcriptionally active (TA) and membrane-bound (MB). Changes in fractions distribution, functional activities and structural reorganization during the cell cycle were found. At the peak of transcription (15 h after PHE) an increase in the relative content of TA and MB fractions as well as an increase of the level of incorporated labelled precursors in RNA of TLA and TA fractions compared to control were observed. At the peak of replication (20 h after PHE) the relative content of TA and MB fractions increased as well, while the level of incorporation of labelled precursors in RNA of TLA and TA fractions was significantly lower than in control.
Asunto(s)
Cromatina/ultraestructura , Regeneración Hepática , Hígado/ultraestructura , Animales , Ciclo Celular , Cromatina/metabolismo , ADN/biosíntesis , Replicación del ADN , Femenino , Hepatectomía , Hígado/metabolismo , ARN/biosíntesis , Ratas , Ratas Wistar , Factores de Tiempo , Transcripción GenéticaRESUMEN
Marked changes in the structural and functional characteristics of liver nuclear chromatin fractions are observed under experimental D-hypovitaminosis, which differ in the degree of transcriptional activity. DNA-polymerase activity and activity of the fraction, enriched with RNA-polymerase I, increases in the active fraction. Free radical LPO reactions are modified in the chromatin fraction with low activity and to the less degree in the active one. Disturbances of chromatine structural properties are caused with the change in the protein and lipid components of chromatin. Administration of ecdysterone preparations (separately and together with vitamin D3) has a partial corrective effect on structural and functional organization of nuclear chromatine. At the action of ecdysterone normalization of LPO reactions modified by pathological changes is observed in the chromatin fraction with low activity and to the less degree in the active one. This kind of influence corrects to the less degree chromatin functional activity and quantitative and qualitative modifications of its protein component. Simultaneous influence of ecdysterone and vitamin D3 leads to the partial normalization of the biochemical indices studied (except for those which characterize LPO reactions) mainly in the active chromatin fraction.
Asunto(s)
Colecalciferol/farmacología , Cromatina/química , Ecdisterona/farmacología , Hígado/química , Deficiencia de Vitamina D/metabolismo , Animales , Fraccionamiento Químico , ADN Polimerasa Dirigida por ADN/efectos de los fármacos , ADN Polimerasa Dirigida por ADN/metabolismo , ARN Polimerasas Dirigidas por ADN/efectos de los fármacos , ARN Polimerasas Dirigidas por ADN/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , Ratas , Ratas Wistar , Relación Estructura-Actividad , Transcripción GenéticaRESUMEN
The study revealed age-related changes in the content and ratio of apoproteins which are part of high-density lipoproteins (HDL), as well as the development of dysapolipoproteinemia. The most significant fall (by 46.7%) was found in the content of the key HDL apoprotein--apoA1, and rise (by 107%)--in apoE. The development of dysapolipoproteinemia was accompanied by changes in the lipid composition of HDL and their subfractions (HDL2 and HDL3). HDLs were enriched by cholesterol and its esters. HDL cholesterol/apoA1 ratio increased twice, while the content of phospholipids decreased.
Asunto(s)
Envejecimiento/sangre , Arteriosclerosis/inmunología , Lipoproteínas HDL/sangre , Animales , Apoproteínas/sangre , Proteínas Sanguíneas/análisis , Inmunidad Innata/fisiología , Lípidos/sangre , Lipoproteínas HDL/química , Ratas , Ratas WistarRESUMEN
Transfer of human ApoA1 gene within the molecular construction which provides its expression, to the liver of the adult and aged rats resulted in the appearance of human protein in their blood, and was accompanied by changes in the content of high-density lipoproteins and of their subclasses HDL(3) and HDL(2), as well as by the shifts in their protein and lipid composition. Synthesis of human ApoA1 was more marked in the organism of adult rats, and gene-regulatory shifts in aged rats.
RESUMEN
The intensity of RNA and protein biosynthesis is studied in different tissues as well as in active and low-active fractions of liver chromatin, when adult and old rats are subjected to emotional-painful stress during 3 days. Significant stimulation of RNA and protein biosynthesis in chromatin fractions in liver and total RNA and protein in adrenals and hypothalamus is observed.
Asunto(s)
Modelos Psicológicos , Dolor/metabolismo , Precursores de Proteínas/biosíntesis , ARN/biosíntesis , Estrés Psicológico/metabolismo , Vísceras/metabolismo , Factores de Edad , Animales , Electrochoque , Masculino , Dolor/etiología , Ratas , Ratas Endogámicas , Estrés Psicológico/etiologíaAsunto(s)
Envejecimiento/genética , Apolipoproteínas A/genética , Lipoproteínas HDL/genética , Transfección/genética , Envejecimiento/sangre , Animales , Apolipoproteína A-I , Apolipoproteínas A/sangre , Clonación Molecular , ADN/genética , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/fisiología , Humanos , Lipoproteínas HDL/sangre , Hígado , Plásmidos/genética , RatasRESUMEN
The template activity, nucleosomal pattern and thermodenaturation parameters of transcriptionally low active (TLA) and transcriptionally active liver chromatin fractions were studied in adult (6-8 months) and old (26-28 months) rats. The following age-related changes of chromatin template properties were found: decrease of endogenous DNA polymerase alpha- and beta-activity in vitro in both chromatin fractions, and redistribution of newly synthetized RNA between mono- and oligonucleosomes in the TLA fraction. These changes are thought to be connected with age-related reorganization of chromatin structure, i.e. with increase of DNA-protein interactions, which stabilize association of chromatin supranucleosomal structures.
Asunto(s)
Envejecimiento/patología , ADN/biosíntesis , Hígado/ultraestructura , Envejecimiento/genética , Envejecimiento/metabolismo , Animales , Cromatina/metabolismo , ADN/genética , Femenino , Expresión Génica , Hígado/metabolismo , Nucleosomas/ultraestructura , Ratas , Ratas Endogámicas , Transcripción GenéticaRESUMEN
The transcriptional activity, nucleosomal patterns, and thermodenaturation parameters of low-active and active fractions of liver chromatin were studied in adult (6-8 mo) and old (26-28 mo) rats at 2, 4, and 6 weeks after partial hepatectomy. At 2 weeks postoperatively, there was a decrease in relative specific radioactivity (RSR) of the active chromatin fraction in adult rats, which returned to normal by the 4th week, while in the low-active fraction it was decreased throughout all the studied regeneration periods. The decrease of the low-active fraction RSR was attended with changes in the nucleosomal organization and DNA-protein interactions revealed by electrophoresis and thermodenaturation. Old rats were found to have the active fraction RSR unchanged throughout all the studied regeneration periods. The low-active fraction RSR increased at 2 and 4 postoperative weeks and decreased to the level of intact liver at 6 weeks. Electrophoretic analysis and parameters of thermodenaturation of the low-active fraction reflect changes in the chromatin conformation associated with transcription activation and, at the same time, reveal its higher compactness in nucleosomal structures. Age differences in the time-course of structural rearrangements and transcriptional activity of liver chromatin during regeneration may be responsible for different rates of postoperative liver restoration in adult and old rats.