1,721,051 research outputs found
Effects of hypoxia and pharmacological treatment on enzyme activities in skeletal muscle of rats of different ages
No full textThe activities of enzymes related to energy metabolism in the gastrocnemius and soleus muscles in young-adult (4 months), mature (12 months), and senescent (24 months) rats were compared after continuous (72 consecutive h) exposure to normobaric hypoxia or normoxia after the vasodilator naftidrofuryl or saline solution had been given intraperitoneally for 30 consecutive days. The maximum rats (Vmax) of the following enzyme activities in the crude extract and/or the crude mitochondrial fraction of each muscle specimen were evaluated for: the anaerobic glycolytic pathway (hexokinase, phosphofructokinase, pyruvate kinase, and lactate dehydrogenase), the tricarboxylic acid cycle (citrate synthase, and malate dehydrogenase), the electron transfer chain (cytochrome oxidase), and the NAD+/NADH redox state (total NADH cytochrome c reductase). The significance of differences between the enzyme activities at different ages or under different experimental conditions in the two tissue preparations of the two muscles were determined by ANOVA. MCA and ETA2 were used to evaluate the net effects of the experimental conditions. First, aging did not seem to affect the soleus and gastrocnemius muscles in the same way. In the gastrocnemius muscle, the major changes were seen in enzymes of the glycolytic pathway, in the crude extracts. In the soleus muscle, the more striking changes in enzyme activities as a function of aging were found in the crude mitochondrial fraction. We also found that hypoxia caused more important changes in 12-month-old rats than in those of other ages (especially the enzyme activities of the gastrocnemius muscle). Naftidrofuryl modified the effects of hypoxia only sometimes and further investigations are necessary before we can draw any conclusions about the pharmacological activity of naftidrofuryl in hypoxi
Relationships between gamma-aminobutyrate and succinate cycles during and after cerebral ischemia
No full textSome metabolites (glycogen, glucose, glucose-6-phosphate, pyruvate, lactate, citrate, alpha-ketoglutarate, succinate, fumarate, malate, glutamate, aspartate, gamma-aminobutyrate, glutamine, alanine, NH+4) were measured in rat cerebral cortex after 5 minutes of complete compression ischemia, as well as after 5, 15, or 30 minutes of recirculation following 5 minutes of ischemia. Complete ischemia induced a drop of glycolytic substrates and intermediates, consistent with the increase of lactate, succinate, alanine, and gamma-aminobutyrate, and with the decrease of malate, fumarate, and alpha-ketoglutarate. These events may be regarded as an expression of the activation of the gamma-aminobutyrate cycle and of the succinate cycle, where succinate itself, in the absence of O2, acts as a terminal electron acceptor. During post-ischemic recovery, cerebral parameters tended to normalize, except for the further increase of alanine and the still higher than normal content of both succinate and gamma-aminobutyrate, as an expression of the possible activation of the gamma-glutamyl and gamma-aminobutyrate cycles during recover
Metabolite concentrations in skeletal muscle of different aged rats submitted to hypoxia and pharmacological treatment with nicergoline
No full textSarcopenic obesity: An appraisal of the current status of knowledge and management in elderly people
No full textToday's increased life expectancy highlights both age-related changes in body composition and a higher prevalence of obesity. Sarcopenic obesity (SO) is assuming a prominent role in cardio-metabolic risk because of the double metabolic burden derived from low muscle mass (sarcopenia) and excess adiposity (obesity). This review evaluates the related studies that have been published over the past 10 years in order to give an updated overview of this new syndrome. There is no consensus on the definition of SO due to the wide heterogeneity of diagnostic criteria and choice of body composition components needed to assess this phenotype. There is a growing body of evidence that the ethio-pathogenesis of SO is complex and multi-factorial, as the consequences are a combination of the outcomes of both sarcopenia and obesity, where the effects are maximised. In order to manage SO, it is important to make lifestyle changes that incorporate weight loss, physical exercise and protein supplementatio
UDP-glucose effect on phrenic diaphragm preparation of the rat
No full textThe effects of uridine-5'-diphosphoglucose (UDPG) on the contractile response of the phrenic nerve-diaphragm preparation and on carbohydrate metabolism in the diaphragmatic muscle were studied in the rat. In the preparations obtained form rats, the contracturant action of UDPG, previously observed in guinea-pig preparations, was thus confirmed. This action was compared with those of uridine, UMP and UDP. Uridine alone was ineffective, while the higher concentration of both UMP and UDP induced a contracture comparable with that shown for the lower concentration of UDPG. This indicates that the action of UDPG is partially related at least to one phosphate-group into its molecular structure. In addition, several substrates and intermediates related to carbohydrate metabolism (glycogen, glucose, glucose-6-phosphate) were measured in the diaphragm, their concentrations proving unaffected by UDPG perfusio
Analisi biochimica sul testicolo e sul gastrocnemio di topi nutriti con soia geneticamente modificata
No full textIn vitro action of uridine diphosphate glucose (UDPG) on phrenic diaphragm preparations
No full textThe action of uridine-5'-diphosphoglucose (UDPG) on the contractile response of the phrenic diaphragm preparation from guinea pig was investigated. UDPG activity was assayed on the preparation at rest or during the exercise; in this case indirect electrical stimulation of phrenic diaphragm preparation or direct stimulation of denervated or curarized muscle were employed. Krebs' solutions adequately modified with regard to glucose concentration were used. The effect of UDPG on the neuromuscular junction was also investigated by recording miniature end plate potentials. An effect of the drug on neuromuscular transmission and on glucose metabolism could be demonstrate
Effect of hypoxia, aging and pharmacological treatment on muscular metabolites and enzyme activities
No full textThe effect of hypoxia and post-hypoxic recovery were studied in gastrocnemius muscle of young-adult and mature beagle dogs. Furthermore, the possible interference of pharmacological treatment with nicergoline was evaluated in these conditions. Muscular glycolytic fuels, intermediates and end-products (glycogen, glucose, glucose 6-phosphate, pyruvate, lactate), Kreb's cycle intermediates (citrate, alpha-ketoglutarate, succinate, malate) and related free amino acids (glutamate, alanine), ammonium ion, energy store and mediators (ATP, ADP, AMP and creatine phosphate), and the energy charge potential were evaluated. Furthermore, in the crude extract and/or mitochondrial fraction of another portion of the same gastrocnemius muscle the maximum rate (Vmax) of some muscular enzymes related to the anaerobic glycolytic pathway (hexokinase, lactate dehydrogenase), the Kreb's cycle (citrate synthase, malate dehydrogenase), the aminoacid pool related to the Krebs' cycle (glutamate dehydrogenase and aspartate aminotransferase), the electron transfer chain (cytochrome oxidase) and NAD+/NADH exchanges (total NADH cytochrome c reductase) was evaluated. Some glycolytic metabolites and Krebs' cycle intermediates were modified by acute hypoxia, while free amino acids and energy mediators remained practically unchanged. The pharmacological treatment maintained the glucose and succinate muscular concentrations within the normal range, during hypoxia. The behaviour of muscular metabolites during hypoxia and/or post-hypoxic recovery is an age-related event. In fact, only in young-adult animals did the altered values return to normal in post-hypoxic recovery. In the present experimental conditions, only minor changes were observed as far as muscular enzyme activities are concerned. In any case, some enzyme activities tested showed different Vmax in young-adult dogs in comparison with mature one
Effect of hypoxia on enzyme activities in skeletal muscle of rats of different ages. An attempt at pharmacological treatment
No full textALS on Italian professional soccer players: the epidemic is still ongoing and soccer-specific
No full textTo assess wether the high risk of ALS is still present in the Italiana soccer cohort and to evaluate the risk for ALS in other professional athlete
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