RESUMO
An optimized method for analysis of free amino acids using a modified lithium-citrate buffer system with a Hitachi L-8800 amino acid analyzer is described. It demonstrates clear advantages over the sodium-citrate buffer system commonly used for the analysis of protein hydrolysates. A sample pretreatment technique for amino acid analysis of brain extracts is also discussed. The focus has been placed on the possibility of quantitative determination of the reduced form of glutathione (GSH) with simultaneous analysis of all other amino acids in brain extracts. The method was validated and calibration coefficient (KGSH) was determined. Examples of chromatographic separation of free amino acids in extracts derived from different parts of the brain are presented.
Assuntos
Aminoácidos/análise , Encéfalo/metabolismo , Cromatografia Líquida de Alta Pressão , Aminoácidos/isolamento & purificação , Animais , Cromatografia por Troca Iônica , Citratos/química , Glutationa/análise , Ratos , Ratos Sprague-Dawley , Ratos WistarRESUMO
Molecular mechanisms of long-term changes in brain metabolism after thiamine administration (single i.p. injection, 400 mg/kg) were investigated. Protocols for discrimination of the activities of the thiamine diphosphate (ThDP)-dependent 2-oxoglutarate and 2-oxoadipate dehydrogenases were developed to characterize specific regulation of the multienzyme complexes of the 2-oxoglutarate (OGDHC) and 2-oxoadipate (OADHC) dehydrogenases by thiamine. The thiamine-induced changes depended on the brain-region-specific expression of the ThDP-dependent dehydrogenases. In the cerebral cortex, the original levels of OGDHC and OADHC were relatively high and not increased by thiamine, whereas in the cerebellum thiamine upregulated the OGDHC and OADHC activities, whose original levels were relatively low. The effects of thiamine on each of the complexes were different and associated with metabolic rearrangements, which included (i) the brain-region-specific alterations of glutamine synthase and/or glutamate dehydrogenase and NADP+-dependent malic enzyme, (ii) the brain-region-specific changes of the amino acid profiles, and (iii) decreased levels of a number of amino acids in blood plasma. Along with the assays of enzymatic activities and average levels of amino acids in the blood and brain, the thiamine-induced metabolic rearrangements were assessed by analysis of correlations between the levels of amino acids. The set and parameters of the correlations were tissue-specific, and their responses to the thiamine treatment provided additional information on metabolic changes, compared to that gained from the average levels of amino acids. Taken together, the data suggest that thiamine decreases catabolism of amino acids by means of a complex and long-term regulation of metabolic flux through the tricarboxylic acid cycle, which includes coupled changes in activities of the ThDP-dependent dehydrogenases of 2-oxoglutarate and 2-oxoadipate and adjacent enzymes.
Assuntos
Aminoácidos/metabolismo , Córtex Cerebral/enzimologia , Complexo Cetoglutarato Desidrogenase/metabolismo , Cetona Oxirredutases/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Tiamina/farmacologia , Animais , Feminino , Ratos , Ratos Sprague-DawleyRESUMO
The effects of chronic intranasal administration of 300 nmol/kg obestatin and its fragment FNAP-NH2 on behavioral activity and nociceptive threshold were examined in male Wistar rats with normal body weight or alimentary obesity. In normal rats, obestatin produced no effect on behavior and nociception, whereas FNAP-NH2 fragment enhanced risk-taking behavior. Rats with excess body weight demonstrated less pronounced risk-taking behavior and elevated nociceptive threshold in comparison with normal animals, but these differences were abolished by chronic administration of FNAP-NH2.
Assuntos
Nociceptividade/efeitos dos fármacos , Oligopeptídeos/farmacologia , Limiar da Dor/efeitos dos fármacos , Hormônios Peptídicos/farmacologia , Administração Intranasal , Sequência de Aminoácidos , Animais , Ansiedade/patologia , Ansiedade/fisiopatologia , Peso Corporal , Ingestão de Alimentos/fisiologia , Masculino , Nociceptividade/fisiologia , Obesidade/patologia , Obesidade/fisiopatologia , Limiar da Dor/psicologia , Ratos , Ratos Wistar , Assunção de RiscosRESUMO
2-Oxo acid dehydrogenase complexes are important metabolic checkpoints functioning at the intercept of sugar and amino acid degradation. This review presents a short summary of architectural, catalytic, and regulatory principles of the complexes structure and function, based on recent advances in studies of well-characterized family members. Special attention is given to use of synthetic phosphonate and phosphinate analogs of 2-oxo acids as selective and efficient inhibitors of the cognate complexes in biological systems of bacterial, plant, and animal origin. We summarize our own results concerning the application of synthetic analogs of 2-oxo acids in situ and in vivo to reveal functional interactions between 2-oxo acid dehydrogenase complexes and other components of metabolic networks specific to different cells and tissues. Based on our study of glutamate excitotoxicity in cultured neurons, we show how a modulation of metabolism by specific inhibition of its key reaction may be employed to correct pathologies. This approach is further developed in our study on the action of the phosphonate analog of 2-oxoglutarate in animals. The study revealed that upregulation of 2-oxoglutarate dehydrogenase complex is involved in animal stress response and may provide increased resistance to damaging effects, underlying so-called preconditioning. The presented analysis of published data suggests synthetic inhibitors of metabolic checkpoints as promising tools to solve modern challenges of systems biology, metabolic engineering, and medicine.
Assuntos
Inibidores Enzimáticos/química , Complexo Cetoglutarato Desidrogenase/química , Ácidos Cetoglutáricos/química , Organofosfonatos/química , Ácidos Fosfínicos/química , Animais , Humanos , Complexo Cetoglutarato Desidrogenase/antagonistas & inibidores , Complexo Cetoglutarato Desidrogenase/fisiologia , Cinética , Mitocôndrias/enzimologiaRESUMO
Single administration of the obestatin fragment 1-4 (300 nmol/kg) to male Wistar rats produced a significant weight loss in male rats on observation days 5-8, while in female rats only on day 8. In addition, males demonstrated decreased risk factor in the elevated plus-maze test, but no effect of the preparation on behavior of female rats was revealed. Obestatin fragment 1-4 had no effect on corticosterone level 1 week after single administration in both females and male rats.
Assuntos
Fármacos Antiobesidade/farmacologia , Oligopeptídeos/farmacologia , Animais , Corticosterona/sangue , Feminino , Masculino , Aprendizagem em Labirinto , Ratos Wistar , Assunção de Riscos , Estresse Psicológico/sangueRESUMO
We studied the effects of anorectic peptide obestatin and its fragment (1-4) on the antioxidant defense system in animals with normal and experimentally induced increased body weight. In rats with normal body weight, no changes in activity of the antioxidant defense system 1 week after single administration of the substances. After chronic administration of obestatin and fragment (1-4) for 1 week, total antioxidant capacity of the plasma decreased; obestatin also lowered the content of TBA-reactive products. In the overweight rats, SOD-like activity in the plasma increased 1 week after chronic administration of obestatin. Hence, obestatin and its fragment (1-4) induced changes in the antioxidant defense system only after chronic administration.
Assuntos
Antioxidantes/análise , Depressores do Apetite/farmacologia , Sobrepeso/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Hormônios Peptídicos/farmacologia , Sequência de Aminoácidos , Animais , Depressores do Apetite/administração & dosagem , Depressores do Apetite/uso terapêutico , Catalase/sangue , Dieta Hiperlipídica/efeitos adversos , Esquema de Medicação , Avaliação Pré-Clínica de Medicamentos , Masculino , Dados de Sequência Molecular , Sobrepeso/sangue , Sobrepeso/etiologia , Fragmentos de Peptídeos/administração & dosagem , Hormônios Peptídicos/administração & dosagem , Hormônios Peptídicos/uso terapêutico , Ratos , Ratos Wistar , Superóxido Dismutase/sangueRESUMO
We studied the effects of the anorexigenic peptide obestatin on the coagulation system and blood rheology (by the parameters of platelet aggregation and osmotic resistance of erythrocytes) in vitro and in vivo. Obestatin inhibited in vitro platelet aggregation in the entire dose range and reduced osmotic resistance of erythrocytes in all doses except 300 nmol/kg (obestatin in a dose of 300 nmol/kg had no effect on this parameter). Similar to the results of in vitro experiments, intranasal, intraperitoneal, and subcutaneous administration of obestatin in a dose of 300 nmol/kg inhibited platelet aggregation and had no effect on the osmotic resistance of erythrocytes.
Assuntos
Pressão Osmótica/efeitos dos fármacos , Hormônios Peptídicos/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Difosfato de Adenosina/metabolismo , Animais , Apetite/efeitos dos fármacos , Coagulação Sanguínea/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Masculino , Óxido Nítrico/biossíntese , RatosRESUMO
This paper considers the transgenerational effects of prenatal stress of different etiology. The impacts of stress factors on the biochemical and morphofunctional parameters of life of the mother, fetus, and offspring in the first and subsequent generations (F1-F4) are estimated. Particular attention is paid to assessing changes in the parameters of physical development, the state of the hypothalamic-pituitary-adrenal axis, proinflammatory status, behavioral indicators, cognitive performance, and vegetative balance in the post-stress period. Contemporary concepts of possible mechanisms of transgenerational transmission of the effects of prenatal stress are considered.
Assuntos
Sistema Hipotálamo-Hipofisário/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Estresse Fisiológico , Animais , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/patologia , Sistema Hipófise-Suprarrenal/metabolismo , Sistema Hipófise-Suprarrenal/patologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/patologiaRESUMO
We studied changes in the autonomic balance of heart regulation (by the parameters of heart rate variability) in non-pregnant female rats and rats on the days 10-11 of pregnancy on the next day after stress provoked by acute hypobaric hypoxia, intermittent normobaric hypoxia, or immobilization. The same parameters were assessed in 36-day-old offspring. In non-pregnant rats, the intermittent hypoxia resulted in a shift of the autonomic balance of heart regulation towards activation of the parasympathetic nervous system; in pregnant females, immobilization led to a shift of the autonomic balance towards the sympathetic nervous system. In the offspring, the changes also depended on the type of stress.
Assuntos
Frequência Cardíaca/fisiologia , Organogênese/fisiologia , Estresse Fisiológico/fisiologia , Animais , Eletrocardiografia , Feminino , Hipóxia/fisiopatologia , Gravidez , Ratos , Restrição Física/fisiologiaAssuntos
Glicemia/metabolismo , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Grelina/farmacologia , Motivação , Animais , Regulação do Apetite , Grelina/administração & dosagem , Grelina/química , Masculino , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos WistarRESUMO
This study analyses the spontaneous behavior and anxiety-phobic status of mature rats that were subjected to antenatal intermittent hypoxia during the early stages of organogenesis. Antenatal intermittent hypoxia caused a decrease of motor activity as well as an enhanced anxiety level in rats of both sexes, while males appeared to be more sensitive to hypoxic influence. The effects of single antenatal intermittent hypoxia were more expressed than those of double exposure.
Assuntos
Ansiedade/fisiopatologia , Comportamento Animal , Hipóxia/fisiopatologia , Atividade Motora , Organogênese , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Ansiedade/etiologia , Feminino , Hipóxia/complicações , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Ratos , Caracteres SexuaisAssuntos
Peso Corporal/efeitos dos fármacos , Ingestão de Líquidos/efeitos dos fármacos , Grelina/farmacologia , Administração Intranasal , Animais , Grelina/administração & dosagem , Grelina/análogos & derivados , Masculino , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos WistarRESUMO
The influence of antenatal intermittent normobaric hypoxia during early organogenesis (days 9-10 of intrauterine development) on the physical development, vegetative balance, and antioxidant defense system of 60-day-old rats was studied. Antenatal exposure to intermittent hypoxia resulted in the impaired physical development of all offspring during the early 15-day postnatal period and caused changes in the vegetative balance of heart regulation, which were differently directed in males and females. Moreover, females that survived antenatal hypoxia had a decreased superoxide dismutase activity in the brain, compared to that in the control rats.
Assuntos
Encéfalo/fisiopatologia , Coração/fisiopatologia , Hipóxia/fisiopatologia , Organogênese , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Animais Recém-Nascidos , Antioxidantes/metabolismo , Encéfalo/embriologia , Feminino , Coração/embriologia , Hipóxia/metabolismo , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Ratos , Caracteres Sexuais , Superóxido Dismutase/metabolismoRESUMO
The survival rate, physical development, and spontaneous behavior has been evaluated in pups of albino rats exposed to acute hypobaric hypoxia on the 9-10th day of gestation corresponding to the onset of organogenesis. Prenatal hypoxia increased the mortality among the offspring, delayed their physical development, and affected their spontaneous behavior up to the age of 2 months. The females exposed to intrauterine hypoxia proved to be more sensitive to hypoxia than males.
Assuntos
Comportamento Animal , Hipóxia/complicações , Complicações na Gravidez , Efeitos Tardios da Exposição Pré-Natal , Animais , Animais Recém-Nascidos , Feminino , Hipóxia Fetal , Masculino , Organogênese , Gravidez , Ratos , Fatores SexuaisRESUMO
The aim of the present study was to investigate the effects of acute hypobaric hypoxia in early organogenesis on three following generations including pregnant females (FO) and two generations of their posterity (F1 and F2). Animals of all generations mentioned above demonstrated marked changes in motor and exploratory activity as well as in anxiety level while the litter of F1 and F2 generations showed also changes in learning ability. Besides, acute hypobaric hypoxia interfered in maternal behavior of females of the FO and F1 generations. The revealed changes kept till pubertal period. Possible mechanisms of gestational stress influence are discussed.
Assuntos
Comportamento Animal/fisiologia , Hipóxia Fetal/fisiopatologia , Organogênese/fisiologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Feminino , Hipóxia Fetal/genética , Masculino , Atividade Motora/genética , Atividade Motora/fisiologia , Organogênese/genética , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , RatosRESUMO
We studied the effect of acute hypobaric hypoxia in early organogenesis on physiological and behavioral parameters of second-generation albino rats. Antenatal acute hypoxia was followed by physical and sexual retardation, increase in the mortality rate, and behavioral changes in second-generation animals (hypoactivity of males and females on day 22 of life and hyperactivity of males on day 57 of life). Second-generation animals exhibited no gender differences in body weight and horizontal and vertical locomotor activity.
Assuntos
Hipóxia/fisiopatologia , Organogênese/fisiologia , Efeitos Tardios da Exposição Pré-Natal , Animais , Animais Recém-Nascidos , Comportamento Animal , Feminino , Masculino , Atividade Motora , Gravidez , Ratos , Fatores SexuaisRESUMO
We studied the effect of acute antenatal hypoxia during the stages of progestation and early organogenesis on some ECG parameters and level of biogenic amines in brain structures in rats. The effect of acute hypoxic exposure during the organogenesis period on the studied parameters was more pronounced than the effect of acute hypoxic exposure during the progestation period. The shift of the autonomic balance towards the sympathetic regulation of cardiac activity is linked with increased content of biogenic amines in the brain stem and cortical structures.
Assuntos
Aminas Biogênicas/metabolismo , Sistema Nervoso Central/metabolismo , Hipóxia Fetal/fisiopatologia , Coração/fisiopatologia , Fatores Etários , Animais , Sistema Nervoso Autônomo/fisiopatologia , Tronco Encefálico/metabolismo , Córtex Cerebral/metabolismo , Dopamina/metabolismo , Eletrocardiografia , Feminino , Hipóxia Fetal/metabolismo , Masculino , Norepinefrina/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ratos , Serotonina/metabolismoRESUMO
Fine scale spatial structure (FSSS) of cytoplasmic genes in plants is thought to be generated via founder events and can be amplified when seeds germinate close to their mother. In gynodioecious species these processes are expected to generate FSSS in sex ratio because maternally inherited cytoplasmic male sterility genes partially influence sex expression. Here we document a striking example of FSSS in both mitochondrial genetic markers and sex in roadside populations of Silene vulgaris. We show that in one population FSSS of sexes influences relative fruit production of females compared to hermaphrodites. Furthermore, FSSS in sex ratio is expected to persist into future generations because offspring sex ratios from females are female-biased whereas offspring sex ratios from hermaphrodites are hermaphrodite-biased. Earlier studies indicated that pollen limitation is the most likely mechanism underlying negative frequency dependent fitness of females. Our results support the theoretical predictions that FSSS in sex ratio can reduce female fitness by decreasing the frequency at which females experience hermaphrodites. We argue that the influence of FSSS on female fitness is complementary to the influence of larger scale population structure on female fitness, and that population structure at both scales will act to decrease female frequencies in gynodioecious species. Better comprehension of the spatial structure of genders and genes controlling sex expression at a local scale is required for future progress toward understanding sex ratio evolution in gynodioecious plants.
Assuntos
DNA Mitocondrial/genética , Razão de Masculinidade , Silene , Genes de Plantas , Marcadores Genéticos , Silene/genéticaRESUMO
Physical development, spontaneous behavior, and training capacity were evaluated in adult progeny of albino rats exposed to acute hypobaric hypoxia on days 9-10 of gestation, corresponding to the early organogenesis period. Prenatal hypoxia caused delayed behavioral disorders, which were more pronounced in females born from mothers with low resistance to hypoxia. Therapeutic intranasal administration of Pro-Gly-Pro peptide in a dose of 1 mg/kg to rat pups on days 13-15 of life completely prevented the negative consequences of acute prenatal hypoxia in adult females and leveled virtually all negative consequences, except delayed physical development, in males.
Assuntos
Hipóxia/complicações , Hipóxia/fisiopatologia , Transtornos Mentais/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Prolina/análogos & derivados , Animais , Feminino , Masculino , Transtornos Mentais/etiologia , Gravidez , Prolina/uso terapêutico , Ratos , Assunção de RiscosRESUMO
The aim of the present study was to compare the survival, physical development and spontaneous behavior of rat pups born from white rats subjected to acute hypobaric hypoxia on the 3rd-5th days of gestation (progestation) period or on the 9-10th day of gestation (period of early organogenesis). It was shown that the delayed effects of progestation hypoxia were less expressed than those following acute hypoxia modeled in the early organogenesis. In latter case, hypoxia led to the increased mortality among rat pups of both sexes while hypoxia-induced delay in physical development and changes in spontaneous behavior and anxiety level were registered up to the 57th day of postnatal period.