Kinetic studies of the Na+-K+-ATPase enzyme system in brain and heart of aging rats

1984 ◽  
Vol 247 (5) ◽  
pp. R850-R855
Author(s):  
L. B. Poole ◽  
M. S. Liu ◽  
P. W. Landfield
Keyword(s):  
Age Differences ◽  
Enzyme System ◽  
Kinetic Studies ◽  
Maximal Velocity ◽  
Age Related ◽  
Age Dependent ◽  
Atpase System ◽  
Old Rats ◽  
K Concentration ◽  
Ouabain Inhibition

Kinetic analyses of the Na+-K+-adenosine triphosphatase (ATPase) system were performed in brain and heart preparations from young mature (4 mo old) and healthy aged (25 mo old) rats. The K+-activated p-nitrophenylphosphatase (K+-pNPPase) method was used to assess activity of the enzyme system. Ouabain inhibition of K+-pNPPase activity was also examined. A significant age-related decrease in maximal velocity (Vmax) was found in cardiac K+-pNPPase activity, but no changes were seen in the K+ concentration for half-maximal velocity (K0.5). No age differences in Vmax or K0.5 were seen for brain. No differences in ouabain inhibition were found in either brain or heart. In a second experiment, the major component of the age-related decline in cardiac K+-pNPPase activity was found to occur between 5 and 14 mo of age, a period during which plasma thyroxine had previously been found to decline in the same animals. Since peripheral Na+-K+-ATPase activity is partly thyroid hormone dependent, the age-dependent decrease in cardiac enzyme activity appears to be secondary to neuroendocrine changes.

scholarly journals Age - related behaviour on individually caged rabbits

2017 ◽  
Vol 62 (1) ◽  
pp. 21 ◽  
Author(s):  
A. KATSAROU (Α. ΚΑΤΣΑΡΟΥ) ◽  
A. TSIRONI (Α. ΤΣΙΡΩΝΗ) ◽  
M. SERAFETINIDOU (Μ. ΣΕΡΑΦΕΤΙΝΙΔΟΥ) ◽  
C. VOYAZAKI (Χ. ΒΟΓΙΑΤΖΑΚΗ) ◽  
V. BAUMANS ◽  
...  
Keyword(s):  
Age Differences ◽  
Environmental Enrichment ◽  
Housing Conditions ◽  
Enrichment Programs ◽  
Video Recordings ◽  
Age Related ◽  
Age Dependent ◽  
Enrichment Program ◽  
Group A

Housing conditions and environmental enrichment of individually caged laboratory rabbits is of great importance for the welfare of the animals and the quality of the experimental results. In order to improve the design of existing environmental enrichment programs for laboratory rabbits, considerable knowledge of the behavioural needs of this species is necessary. Taking this into consideration, the aim of this study was to monitor and analyze the behaviour of juvenile and young adult rabbits in order to establish whether there are any age-dependent differences in grooming, rearing, sniffing, eating, drinking and gnawing. 12 NZW rabbits were divided into two groups: group A consisted of six 6-month-old rabbits (young adults) and group Β consisted of six 2-month-old rabbits (juvenile). All animals were already housed for more than twenty days under the same conditions in the animal facility. Both groups of rabbits were video-recorded between 06:00h - 18:00h for four consecutive days. The frequency of each behaviour was determined and compared in the two groups of rabbits from the video recordings. The frequencies of grooming, eating and gnawing in the young rabbits were significantly greater than those in the older rabbits (p<0.05). No statistical differences were found between the two groups for rearing, sniffing and drinking. From these results, we concluded that even small age differences should be taken into account when designing an environmental enrichment program for individually caged rabbits.

scholarly journals Age differences in retrieval-related reinstatement reflect age-related dedifferentiation at encoding

2020 ◽  
Author(s):  
Paul F. Hill ◽  
Danielle R. King ◽  
Michael D. Rugg
Keyword(s):  
Older Adults ◽  
Age Differences ◽  
Source Memory ◽  
Neural Differentiation ◽  
Memory Performance ◽  
Independent Manner ◽  
Age Related ◽  
Age Dependent ◽  
With Memory ◽  
Age Independent

AbstractAge-related reductions in neural specificity have been linked to cognitive decline. We examined whether age differences in specificity of retrieval-related cortical reinstatement could be explained by analogous differences at encoding, and whether reinstatement was associated with memory performance in an age-dependent or age-independent manner. Young and older adults underwent fMRI as they encoded words paired with images of faces or scenes. During a subsequent scanned memory test participants judged whether test words were studied or unstudied and, for words judged studied, also made a source memory judgment about the associated image category. Using multi-voxel pattern analyses, we identified a robust age-related decline in scene reinstatement. This decline was fully explained by age differences in neural differentiation at encoding. These results suggest that, regardless of age, the specificity with which events are neurally processed at the time of encoding determines the fidelity of cortical reinstatement at retrieval.

scholarly journals MODES OF USE OF THE CELL PHONE AND HEALTH OF SCHOOLCHILDREN

2019 ◽  
Vol 98 (8) ◽  
pp. 857-862 ◽  
Author(s):  
Olga A. Vyatleva ◽  
A. M. Kurgansky
Keyword(s):  
Sleep Disorders ◽  
Age Differences ◽  
Radiation Intensity ◽  
Health Indicators ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Relative Risks ◽  
Age Related ◽  
Age Dependent ◽  
The Impact

Introduction. The broad spread of cell phones (CP) among schoolchildren and the absence of age standards for their safe use determined the purpose of the study: to reveal the regimens of CP use, critical for the health of children and adolescents. Material and methods. In a cross-sectional study in 2008-2010, by the questionnaire data of 2,137 schoolchildren aged 6-15 years there was assessed the impact of CP usage indices (daily number of calls - CN, call duration - CD, and total daily duration of calls - TCDD) on health (the incidence of headaches and sleep disorders, number of colds). Student and Mann-Whitney criteria and assessment of relative risks were used. Results. The study revealed age-dependent critical values of usage indices (in 6-10 years: CN=2, TCDD=6 minutes.; in 11-13 years: CN=6; in 14-15 years CN=6, CD=3 minutes., TCDD=4 -10 min.), the exceeding of which due to risks: in 6-10 years - to have more than 4 colds a year (OR 2.25, 95% CI 1.09-4.62); in 11-13 years to have several headaches per week (OR 1.61, 95% CI 1.12-2.30); in 14-15 years - to have several headaches (OR 1.79, 95% CI 1.27-2.54) and several sleep disorders (OR 1.66, 95% CI 1.17-2.37) per week. Discussion. Age differences in critical modes of CP use and in health violations, as well as the importance of radiation intensity are discussed. Conclusions. Age-related CP use regimens, critical for health, were established. It was shown the need to develop more precise age criteria for safe CP use with taking into account a wider range of health indicators and radiation intensity.

scholarly journals Age-Related Alteration in Serum Adiponectin in Rats and Its Association with Insulin Resistance Markers

2019 ◽  
Author(s):  
Marziyeh Feyzi ◽  
Mohammad Reza Tabandeh ◽  
Mehrdad Shariati ◽  
Mohammad Amin Edalatmanesh
Keyword(s):  
Insulin Resistance ◽  
Male Rats ◽  
Serum Adiponectin ◽  
Oral Glucose ◽  
Dependent Manner ◽  
Age Progression ◽  
Age Related ◽  
Glucose Ingestion ◽  
Age Dependent ◽  
Old Rats

Introduction: Adiponectin is one of the most important adipose derived hormone that conflicting data are available about serum changes of adiponectin at different ages.The present study was done to determine the age related changes in serum adiponectin and its association with insulin resistance (IR) indices in aging in male rats. Methods: In this study, serum samples were obtained from male rats at different ages, including 2, 5, 10, 18, 52 and 72 weeks age (n=10 in each age group). Oral glucose tolerance and glucose stimulated insulin secretion tests were measured using determination of glucose concentrations at 15, 30, 45 and 60 min after oral ingestion of glucose (1 mg/kg body weight) for each animal. Serum adiponectin and insulin levels were determined using species specific ELISA kits. HOMA-IR was calculated based on glucose and insulin concentrations. Data were analyzed using SPSS version 16 software (SPSS Inc., Chicago, IL) also using one way analysis of variance and LSD posthoc tests. Results: Our results showed an age dependent decrease in serum adiponectin concentration, and 72-week old rats had the lowest level of adiponectin compared with those in other ages (p<0.05). IR indices, including fasting glucose, insulin, HOMA-IR and response to oral glucose ingestion was increased in an age dependent manner and 72-week old rats showed the highest levels of the IR indices. Conclusion: Regarding the role of adiponectin in glucose homeostasis and insulin sensitization, it seems that reduction of serum adiponectin with age progression may be an important mechanism of insulin resistance in aging.

scholarly journals Transmission Electron Microscopy Study of Mitochondria in Aging Brain Synapses

Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 171 ◽  
Author(s):  
Vladyslava Rybka ◽  
Yuichiro J. Suzuki ◽  
Alexander S. Gavrish ◽  
Vyacheslav A. Dibrova ◽  
Sergiy G. Gychka ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Age Related ◽  
Transmission Electron ◽  
Age Dependent ◽  
Old Rats ◽  
Synaptic Mitochondria

The brain is sensitive to aging-related morphological changes, where many neurodegenerative diseases manifest accompanied by a reduction in memory. The hippocampus is especially vulnerable to damage at an early stage of aging. The present transmission electron microscopy study examined the synapses and synaptic mitochondria of the CA1 region of the hippocampal layer in young-adult and old rats by means of a computer-assisted image analysis technique. Comparing young-adult (10 months of age) and old (22 months) male Fischer (CDF) rats, the total numerical density of synapses was significantly lower in aged rats than in the young adults. This age-related synaptic loss involved degenerative changes in the synaptic architectonic organization, including damage to mitochondria in both pre- and post-synaptic compartments. The number of asymmetric synapses with concave curvature decreased with age, while the number of asymmetric synapses with flat and convex curvatures increased. Old rats had a greater number of damaged mitochondria in their synapses, and most of this was type II and type III mitochondrial structural damage. These results demonstrate age-dependent changes in the morphology of synaptic mitochondria that may underlie declines in age-related synaptic function and may couple to age-dependent loss of synapses.

Comparison of calcium and magnesium absorption: in vivo and in vitro studies

1990 ◽  
Vol 259 (5) ◽  
pp. G720-G726 ◽  
Author(s):  
L. L. Hardwick ◽  
M. R. Jones ◽  
R. K. Buddington ◽  
R. A. Clemens ◽  
D. B. Lee
Keyword(s):  
Maximal Velocity ◽  
Michaelis Constant ◽  
Age Related ◽  
Ca Uptake ◽  
Old Rats ◽  
Different Levels ◽  
Intact Rats ◽  
Diffusional Component

Transport characteristics of Ca and Mg were compared at three different levels of the absorptive process in male (120-170 g) Wistar rats. Balance studies in intact rats revealed that fractional Ca absorption decreased with increased Ca intake so that net Ca absorption remained constant. Fractional Mg absorption decreased modestly with increased Mg intake so that net Mg absorption increased proportionately with increased dietary Mg. Everted duodenal sacs demonstrated the presence of active Ca absorption with serosal-to-mucosal (S/M) ratio of 2.65 +/- 0.20 (n = 6), which was greater than unity (P less than 0.001). In contrast, the S/M for Mg did not exceed unity. Mucosal duodenal Ca uptake exhibited a large saturable (Michaelis constant of 4.80 +/- 0.34 mM, maximal velocity of 4.71 +/- 0.13 nmol.min-1.mg-1) and a small nonsaturable component (0.12 +/- 0.01 nmol.min-1.mg-1) in 5-wk-old rats (120 g). In 72-wk-old rats (600 g) the diffusional component of Ca uptake became predominant, and the slope increased significantly to 0.32 +/- 0.01 (P less than 0.05). Duodenal Mg uptake was completely concentration dependent and exhibited no age-related changes.

Age-dependent increase in hydrogen peroxide production by cardiac monoamine oxidase A in rats

2003 ◽  
Vol 284 (4) ◽  
pp. H1460-H1467 ◽  
Author(s):  
Agnès Maurel ◽  
Carole Hernandez ◽  
Oksana Kunduzova ◽  
Guy Bompart ◽  
Claudie Cambon ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Western Blot ◽  
Enzyme Assay ◽  
Monoamine Oxidase A ◽  
Pcr Analysis ◽  
Mao B ◽  
Age Related ◽  
Age Dependent ◽  
Mao A ◽  
Old Rats

Oxidative stress is one of the factors involved in age-related impairment of cardiac function. In the present study, we investigated the role of the catecholamine-degrading enzyme monoamine oxidase (MAO) in H2O2production in the hearts of young, adult, and old rats. MAO-dependent H2O2production, measured by a chemiluminescence-based assay, increased with age, reaching the maximum in 24-mo-old rats (7.5-fold increase vs. 1-mo-old rats). The following observations indicate that the age-dependent increase in H2O2generation was fully related to the MAO-A isoform: 1) at all the ages tested, chemiluminescence production was inhibited by the MAO-A inhibitor clorgyline but not by the MAO-B inhibitor RO-19 6327; 2) enzyme assay, Western blot, and semiquantitative RT-PCR analysis showed an age-dependent increase in cardiac MAO-A activity, immunodetection, and mRNA expression, respectively; and 3) the MAO-B isoform was undetectable by enzyme assay and Western blot analysis. These results suggest that MAO-A could be a major source of H2O2in the aging heart.

scholarly journals Age Differences In Retrieval-Related Reinstatement Reflect Age-Related Dedifferentiation At Encoding

2020 ◽  
Vol 31 (1) ◽  
pp. 106-122 ◽  
Author(s):  
Paul F Hill ◽  
Danielle R King ◽  
Michael D Rugg
Keyword(s):  
Age Differences ◽  
Memory Performance ◽  
Independent Manner ◽  
Younger Adults ◽  
Age Related ◽  
Pattern Similarity ◽  
Age Dependent ◽  
Neural Selectivity ◽  
With Memory ◽  
Robust Evidence

Abstract Age-related reductions in neural selectivity have been linked to cognitive decline. We examined whether age differences in the strength of retrieval-related cortical reinstatement could be explained by analogous differences in neural selectivity at encoding, and whether reinstatement was associated with memory performance in an age-dependent or an age-independent manner. Young and older adults underwent fMRI as they encoded words paired with images of faces or scenes. During a subsequent scanned memory test participants judged whether test words were studied or unstudied and, for words judged studied, also made a source memory judgment about the associated image category. Using multi-voxel pattern similarity analyses, we identified robust evidence for reduced scene reinstatement in older relative to younger adults. This decline was however largely explained by age differences in neural differentiation at encoding; moreover, a similar relationship between neural selectivity at encoding and retrieval was evident in young participants. The results suggest that, regardless of age, the selectivity with which events are neurally processed at the time of encoding can determine the strength of retrieval-related cortical reinstatement.

Age-Related Attenuation of Aerobic Exercise Training Adaptation in 24-Week Old Rats

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1916-P
Author(s):  
REBECCA L. SCALZO ◽  
GRAHAME F. EVANS ◽  
SARA E. HULL ◽  
LESLIE KNAUB ◽  
LORI A. WALKER ◽  
...  
Keyword(s):  
Exercise Training ◽  
Aerobic Exercise ◽  
Aerobic Exercise Training ◽  
Training Adaptation ◽  
Age Related ◽  
Old Rats

Peroxidases from Tulip Bulbs (Tulipa fosteriana, L.) Oxidize Xenobiotics NNitrosodimethylamine and N-Nitroso-N-methylaniline in vitro

1997 ◽  
Vol 62 (11) ◽  
pp. 1804-1814 ◽  
Author(s):  
Marie Stiborová ◽  
Hana Hansíková
Keyword(s):  
Cytochromes P450 ◽  
Kinetic Studies ◽  
The Other ◽  
Maximal Velocity ◽  
Michaelis Constant ◽  
Other Hand ◽  
Plant Peroxidases ◽  
Tulip Bulbs

Tulip bulbs (Tulipa fosteriana, L.) contain peroxidases catalyzing the oxidation of the xenobiotics N-nitrosodimethylamine (NDMA) and N-nitroso-N-methylaniline (NMA). Three anionic (A1, A2, A3) and four cationic (B, C, D, E) peroxidases were purified from this tissue, partially characterized and used for kinetic studies. Demethylation of NDMA and NMA producing formaldehyde is catalyzed by one anionic (A1) and three cationic (C, D, E) peroxidases. The oxidation of NDMA by tulip peroxidases exhibits the Michaelis-Menten kinetics. The apparent Michaelis constant and the maximal velocity values for this substrate were determined. On the other hand, non-Michaelian kinetics for the NMA oxidation were observed with tulip peroxidases. The most abundant cationic peroxidase (peroxidase C) was used for detailed enzymatic studies. In addition to formation of formaldehyde, methylaniline, aniline, 4-aminophenol and phenol were found to be metabolites formed from NMA. Phenol was formed presumably by N-demethylation via a benzenediazonium ion, while methylaniline, aniline and 4-aminophenol were products of denitrosation of the substrate. The efficiencies of plant peroxidases to oxidize NDMA and NMA in vitro are compared with those of cytochromes P450 and discussed.

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