scholarly journals Smaller organ mass with greater age, except for heart

2009 ◽  
Vol 106 (6) ◽  
pp. 1780-1784 ◽  
Author(s):  
Qing He ◽  
Stanley Heshka ◽  
Jeanine Albu ◽  
Lawrence Boxt ◽  
Norman Krasnow ◽  
...  
Keyword(s):  
African Americans ◽  
The Elderly ◽  
Left Ventricular ◽  
Fat Free Mass ◽  
Whole Body ◽  
Organ Mass ◽  
Total Body ◽  
Age Range ◽  
Negative Relationships

Autopsy/cadaver data indicate that many organs and tissues are smaller in the elderly compared with young adults; however, in vivo data are lacking. The aim of this study was to determine whether the mass of specific high-metabolic-rate organs is different with increasing age, using MRI. Seventy-five healthy women (41 African-Americans and 34 Caucasians, age range 19–88 yr) and 36 men (8 African-Americans and 28 Caucasians, age range 19–84 yr) were studied. MRI-derived in vivo measures of brain, heart, kidneys, liver, and spleen were acquired. Left ventricular mass (LVM) was measured by either echocardiography or cardiac gated MRI. Total body fat mass and fat-free mass (FFM) were measured with a whole body dual-energy X-ray absorptiometry (DXA) scanner. Multiple regression analysis was used to investigate the association between the organ mass and age after adjustment for weight and height (or DXA measures of FFM), race, sex, and interactions among these variable. No statistically significant interaction was found among age, sex, and race in any regression model. Significant negative relationships between organ mass and age were found for brain ( P < 0.0001), kidneys ( P = 0.01), liver ( P = 0.001), and spleen ( P < 0.0001). A positive relationship between LVM and age was found after adjustment for FFM ( P = 0.037). These findings demonstrate that age has a significant effect on brain, kidneys, liver, spleen, and heart mass. The age effect was independent of race and sex.

scholarly journals Metabolically active portion of fat-free mass: a cellular body composition level modeling analysis

2007 ◽  
Vol 292 (1) ◽  
pp. E49-E53 ◽  
Author(s):  
ZiMian Wang ◽  
Stanley Heshka ◽  
Jack Wang ◽  
Dympna Gallagher ◽  
Paul Deurenberg ◽  
...  
Keyword(s):  
Water Distribution ◽  
Cell Mass ◽  
Extracellular Fluid ◽  
Multiple Linear Regression Model ◽  
Resting Energy Expenditure ◽  
Cellular Level ◽  
Fat Free Mass ◽  
Whole Body ◽  
Total Body

The proportion of fat-free mass (FFM) as body cell mass (BCM) is highly related to whole body resting energy expenditure. However, the magnitude of BCM/FFM may have been underestimated in previous studies. This is because Moore's equation [BCM (kg) = 0.00833 × total body potassium (in mmol)], which was used to predict BCM, underestimates BCM by ∼11%. The aims of the present study were to develop a theoretical BCM/FFM model at the cellular level and to explore the influences of sex, age, and adiposity on the BCM/FFM. Subjects were 112 adults who had the following measurements: total body water by2H2O or3H2O dilution; extracellular water by NaBr dilution; total body nitrogen by in vivo neutron activation analysis; and bone mineral by dual-energy X-ray absorptiometry. FFM was calculated using a multicomponent model and BCM as the difference between FFM and the sum of extracellular fluid and solids. The developed theoretical model revealed that the proportion of BCM to FFM is mainly determined by water distribution (i.e., E/I, the ratio of extracellular to intracellular water). A significant correlation ( r = 0.90, P < 0.001) was present between measured and model-predicted BCM/FFM for all subjects pooled. Measured BCM/FFM [mean (SD)] was 0.584 ± 0.041 and 0.529 ± 0.041 for adult men and women ( P < 0.001), respectively. A multiple linear regression model showed that there are independent significant associations of sex, age, and fat mass with BCM/FFM.

Short-term exercise improves myocardial tolerance to in vivo ischemia-reperfusion in the rat

2001 ◽  
Vol 91 (5) ◽  
pp. 2205-2212 ◽  
Author(s):  
Haydar A. Demirel ◽  
Scott K. Powers ◽  
Murat A. Zergeroglu ◽  
R. Andrew Shanely ◽  
Karyn Hamilton ◽  
...  
Keyword(s):  
Heat Stress ◽  
Maximum Rate ◽  
Treadmill Exercise ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Antioxidant Defenses ◽  
Whole Body ◽  
Sprague Dawley ◽  
Short Term

These experiments examined the independent effects of short-term exercise and heat stress on myocardial responses during in vivo ischemia-reperfusion (I/R). Female Sprague-Dawley rats (4 mo old) were randomly assigned to one of four experimental groups: 1) control, 2) 3 consecutive days of treadmill exercise [60 min/day at 60–70% maximal O2 uptake (V˙o 2 max)], 3) 5 consecutive days of treadmill exercise (60 min/day at 60–70%V˙o 2 max), and 4) whole body heat stress (15 min at 42°C). Twenty-four hours after heat stress or exercise, animals were anesthetized and mechanically ventilated, and the chest was opened by thoracotomy. Coronary occlusion was maintained for 30-min followed by a 30-min period of reperfusion. Compared with control, both heat-stressed animals and exercised animals (3 and 5 days) maintained higher ( P < 0.05) left ventricular developed pressure (LVDP), maximum rate of left venticular pressure development (+dP/d t), and maximum rate of left ventricular pressure decline (−dP/d t) at all measurement periods during both ischemia and reperfusion. No differences existed between heat-stressed and exercise groups in LVDP, +dP/d t, and −dP/d t at any time during ischemia or reperfusion. Both heat stress and exercise resulted in an increase ( P < 0.05) in the relative levels of left ventricular heat shock protein 72 (HSP72). Furthermore, exercise (3 and 5 days) increased ( P < 0.05) myocardial glutathione levels and manganese superoxide dismutase activity. These data indicate that 3–5 consecutive days of exercise improves myocardial contractile performance during in vivo I/R and that this exercise-induced myocardial protection is associated with an increase in both myocardial HSP72 and cardiac antioxidant defenses.

A Study of Changes in Whole-Body Calcium, Phosphorus, Sodium and Nitrogen by Neutron Activation Analysis in Vivo in Rats on a Calcium-Deficient Diet

1976 ◽  
Vol 51 (4) ◽  
pp. 399-402
Author(s):  
K. Boddy ◽  
R. Lindsay ◽  
I. Holloway ◽  
D. A. S. Smith ◽  
A. Elliott ◽  
...  
Keyword(s):  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
The Body ◽  
Whole Body ◽  
Deficient Diet ◽  
Calcium Phosphorus ◽  
Dietary Period ◽  
Total Body ◽  
And Control

1. A method of measuring changes in the total body content of calcium, phosphorus, nitrogen and sodium in rats by activation analysis in vivo is described. 2. The change in the body content of the elements has been measured in rats on a calcium-deficient diet and in control animals, the body nitrogen being used to represent lean body mass for normalization. 3. There were significant differences in Ca/N and P/N but not in Ca/P ratios between the animals on a deficient diet and control animals at the end of the dietary period.

Total Body Potassium and Body Fat Estimation in Relationship to Height, Sex, Age, Malnutrition and Obesity

1975 ◽  
Vol 48 (5) ◽  
pp. 431-440 ◽  
Author(s):  
C. J. Edmonds ◽  
B. M. Jasani ◽  
T. Smith
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Body Fat ◽  
Fat Free Mass ◽  
Whole Body ◽  
Regression Equations ◽  
Total Body Potassium ◽  
Normal Individuals ◽  
Males And Females ◽  
Total Body

1. Total body potassium was estimated by 40K measurement with a high-sensitivity whole-body counter in normal individuals over a wide age range and in patients who were obese or were grossly wasted as a result of various conditions which restricted food intake. 2. Potassium concentration (mmol/kg body weight) fell with increasing age over 30 years in both normal males and females, but when individuals of different age groups were matched for height, a significant fall in total body potassium with increasing age was observed only in males. Total body potassium of females was about 75% that of males of similar height when young, the sex difference decreasing with ageing. In the normal population, total body potassium was significantly correlated with height and with weight; regression equations for various relationships are given. 3. Fat-free mass was estimated from total body potassium, values of 65 and 56 mmol of potassium/kg fat-free mass being used for males and females respectively. Body fat estimated by this method correlated well with skinfold measurements over a wide range of body weight but in malnourished individuals having inadequate food intake there was considerable discrepancy and present formulae for estimating fat-free mass from total body potassium appear unsatisfactory in malnutrition. Considerable differences between expected and observed values of total body potassium were found in muscular individuals and in normal individuals who were thin but whose body weight was relatively constant. 4. The patients with malnutrition were low both in body fat as estimated by skinfold thickness and in total body potassium estimated on the basis of height. Plasma potassium was, however, normal and potassium supplements did not increase the total body potassium. 5. Total body potassium of obese individuals was not significantly different from that of normal weight individuals on the basis of height. Total body potassium fell on weight reduction with a very low energy diet of 1260 kJ (300 kcal.) daily but changed little with a 3300 kJ (800 kcal.) diet over several months' observation. 6. For overweight, obese individuals, total body potassium was best predicted from the individual's height. For those whose body weight was less than expected, the use of weight gave the best prediction but the error was considerable when the weight deviation was large.

scholarly journals Effects of whole-body electromyostimulation on function, muscle mass, strength, social participation, and falls-efficacy in older people: A randomized trial protocol

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245809
Author(s):  
Túlio Medina Dutra de Oliveira ◽  
Diogo Carvalho Felício ◽  
José Elias Filho ◽  
João Luiz Quagliotti Durigan ◽  
Diogo Simões Fonseca ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Social Participation ◽  
Positive Impact ◽  
The Elderly ◽  
Good Choice ◽  
Fat Free Mass ◽  
Whole Body ◽  
Control Group ◽  
Before And After ◽  
Physical Limitations

Background Resistance training has a positive impact on functional capacity and muscle mass in the elderly. However, due to physical limitations or a simple aversion against regular exercise, a majority of the elderly do not reach the recommended exercise doses. This led us to evaluate the effect of whole-body electromyostimulation (WB-EMS), a novel, time-efficient, and smooth training technology on physical function, fat-free mass, strength, falls-efficacy, and social participation of the elderly. Methods The present study is a randomized, parallel group clinical trial approved by the Ethics Committee of our Institution. Sixty-six volunteers (age ≥ 60 years) will be recruited from the geriatric outpatient department in a tertiary hospital and primary care units and randomized into two groups: WB-EMS group or active control group (aCG). The WB-EMS or aCG protocol will consist of 16 sessions for 8 consecutive weeks, twice per week. The primary outcomes will be maximal isometric knee extension (IKE), functional lower extremity strength, fat-free mass, gait speed, and risk of falls measured before and after intervention. The secondary outcomes will be social participation and falls-efficacy assessed before and after the intervention and at three and six months of follow-up. Participant’s satisfaction with and awareness of electrical stimulation therapy will also be assessed immediately after the 8-week intervention. Discussion Patients receiving WB-EMS exercises are believed to have better outcomes than those receiving conventional, more time-consuming resistance exercises. Hence, innovative, time-efficient, joint-friendly, and highly individualized exercise technologies (such as WB-EMS) may be a good choice for the elderly with time constraints, physical limitations, or little enthusiasm, who are exercising less than the recommended amounts for impact on muscle mass, strength, and function.

BODY ORGAN CYTOCHROME OXIDASE ACTIVITY IN COLD- AND WARM-ACCLIMATED RATS

1963 ◽  
Vol 41 (9) ◽  
pp. 1847-1854 ◽  
Author(s):  
Ladislav Janský
Keyword(s):  
Steady State ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Whole Body ◽  
Cytochrome Oxidase Activity ◽  
Full Capacity ◽  
Body Organ ◽  
Total Body

The cytochrome oxidase activity was estimated in homogenates of the whole body and in nine body organs of cold- and warm-acclimated rats. The total body cytochrome oxidase activity expressed in terms of oxygen consumption was similar in cold- and warm-acclimated rats. In cold-acclimated animals the total cytochrome oxidase activity did not differ from maximal steady state metabolism measured in vivo, while in warm-acclimated rats the total cytochrome oxidase activity was almost twice as great as the maximal steady state metabolism. The results indicate that warm-acclimated rats do not utilize the full capacity of the cytochrome system and that cold-acclimation makes full exploitation of the oxidase capacity possible. In cold-acclimated rats the cytochrome oxidase activity of the muscles comprised 57% of the total, the liver 22.5%, and the skin 6%, with smaller roles for other organs. The role of the liver was greater in cold-acclimated than in warm-acclimated rats.

Influence of muscular development, obesity, and age on the fat-free mass of adults

1976 ◽  
Vol 41 (2) ◽  
pp. 223-229 ◽  
Author(s):  
J. Womersley ◽  
J. V. Durnin ◽  
K. Boddy ◽  
M. Mahaffy
Keyword(s):  
Body Fat ◽  
The Body ◽  
Fat Free Mass ◽  
Potassium Content ◽  
Whole Body ◽  
Obese Women ◽  
Men And Women ◽  
Muscular Development ◽  
Total Body ◽  
Water Measurement

Body fat and the fat-free mass (FFM) were estimated in 36 men and 43 women deliberately chosen to represent a variety of physical types; these were 1) young sedentary, 2) “muscular,” 3) younger obese, 4) older obese, and 5) older nonobese individuals of both sexes. The body fat and the FFM were estimated from measurements of body density (by total immersion in water, measurement being made of the residual volume of air present in the lungs at immersion) and from measurements of total body potassium (using a whole-body monitor to assess the natural 40K isotope present in the body). The muscular men and women and the younger obese men and women had a considerably greater FFM and thus had greater quantities of potassium than the corresponding sedentary groups. There were significantly different estimates of the FFM calculated from density and from total body K in three groups, the sedentary young men, the muscular, and the younger obese women. The density and the potassium content of the FFM appear to decline with obesity and aging. Muscular development is associated with a decrease in the density but an increase in the potassium content of the FFM.

Gastrointestinal tract, hepatic, hindlimb, and renal recovery of CO2 in vivo

2000 ◽  
Vol 89 (5) ◽  
pp. 2000-2006 ◽  
Author(s):  
Jennifer D. Gresham ◽  
Koji Okamura ◽  
Phillip E. Williams ◽  
Kareem Jabbour ◽  
Paul J. Flakoll
Keyword(s):  
Gastrointestinal Tract ◽  
Pool Size ◽  
In Vivo Studies ◽  
Whole Body ◽  
Constant Infusion ◽  
Potential Contribution ◽  
Experimental Conditions ◽  
Rate Of Decay ◽  
Total Body

Whole body oxidative rates of labeled substrates are often measured by collecting expired air and determining the amount of labeled CO2 that is produced. However, the CO2 produced may not be completely recovered under all circumstances, and there is a wide variation in values reported under different experimental conditions (∼50–100%). The potential contribution of specific organs to this variation has not been defined. In vivo studies using healthy, postabsorptive, multicatheterized conscious canines were conducted to determine gastrointestinal tract, hepatic, hindlimb, and renal recoveries of NaH14CO3 during a 180-min constant infusion [0.022 ± 0.002 (SE) μCi · kg−1 · min−1]. Before the constant infusion period, a bolus infusion of NaH14CO3 (1.76 ± 0.16 μCi/kg) was given, and the rate of decay in blood was measured over a 15-min period to determine pool size. The pool size for the distribution of14CO2 was ∼80% of the total body pool (16.0 ± 1.7 liters). Whole body recovery was 97.2 ± 6.7%. The recoveries across the liver, gut, leg, and kidney were 99.9 ± 1.3, 98.0 ± 1.4, 96.7 ± 2.6, and 99.9 ± 2.1%, respectively. In conclusion, hepatic, gastrointestinal tract, hindlimb, and renal recoveries of CO2 in vivo were near 100%, suggesting that CO2 loss is not greater in gluconeogenic organs and that corrections for incomplete recovery of CO2, when measuring oxidation of substrates across these organs under normal postabsorptive conditions, would be very minor.

scholarly journals Practical Aspects of Volume Control in Chronic Kidney Disease Using Whole Body Bioimpedance

2015 ◽  
Vol 39 (1-3) ◽  
pp. 32-36 ◽  
Author(s):  
Elizabeth L. Oei ◽  
Stanley L. Fan
Keyword(s):  
New Technologies ◽  
Fluid Management ◽  
Dry Weight ◽  
Residual Renal Function ◽  
Left Ventricular ◽  
Whole Body ◽  
Volume Control ◽  
Dialysis Patients ◽  
Additional Information ◽  
Total Body

Background: Fluid status is an independent predictor of mortality in dialysis patients. Current methods of fluid assessment have several limitations. Summary: An ideal method should be cheap, portable, easy to perform without extensive training, reproducible and determines patients' excess or deficit of total body water. Bioimpedance analysis (BIA) fulfils many of these criteria and can give additional information on fat and lean tissue composition. The accuracy and precision of BIA has been shown to be equivalent to the ‘gold standard' direct estimation techniques. Key Messages: Although there remains some concern about its validity in dialysis patients, fluid overload determined by BIA has been shown to predict mortality. BIA-guided fluid management appears superior to conventional fluid management in achieving clinically important outcomes such as reduction in blood pressure, left ventricular mass index, and arterial stiffness. Accurate setting of dry weight might also help preserve residual renal function by limiting episodes of dehydration. Nevertheless, as with all new technologies, there are issues that still need to be resolved. This will be achieved only with larger prospective interventional studies to explore its specific roles in dialysis cohorts.

scholarly journals Circulating levels of cytochromecafter resuscitation from cardiac arrest: a marker of mitochondrial injury and predictor of survival

2007 ◽  
Vol 292 (2) ◽  
pp. H767-H775 ◽  
Author(s):  
Jeejabai Radhakrishnan ◽  
Sufen Wang ◽  
Iyad M. Ayoub ◽  
Julieta D. Kolarova ◽  
Rita F. Levine ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cytochrome C ◽  
Left Ventricular ◽  
Whole Body ◽  
Stroke Work ◽  
Western Immunoblotting ◽  
Mitochondrial Injury ◽  
Ventricular Tissue ◽  
Apoptotic Pathways

Ca2+overload and reactive oxygen species can injure mitochondria during ischemia and reperfusion. We hypothesized that mitochondrial injury occurs during cardiac resuscitation, causing release of cytochrome c to the cytosol and bloodstream while activating apoptotic pathways. Plasma cytochrome c was measured using reverse-phase HPLC and Western immunoblotting in rats subjected to 4 or 8 min of untreated ventricular fibrillation and 8 min of closed-chest resuscitation followed by 240 min of postresuscitation hemodynamic observation. A sham group served as control. Plasma cytochrome c rose progressively to levels 10-fold higher than in sham rats 240 min after resuscitation ( P < 0.01), despite reversal of whole body ischemia (decreases in arterial lactate). Cytochrome c levels were inversely correlated with left ventricular stroke work ( r = −0.40, P = 0.02). Western immunoblotting of left ventricular tissue demonstrated increased levels of 17-kDa cleaved caspase-3 fragments in the cytosol. Plasma cytochrome c was then serially measured in 12 resuscitated rats until the rat died or cytochrome c returned to baseline. In three survivors, cytochrome c rose slightly to ≤2 μg/ml and returned to baseline within 96 h. In nine nonsurvivors, cytochrome c rose progressively to significantly higher maximal levels [4.6 (SD 2.0) vs. 1.6 (SD 0.3) μg/ml, P = 0.029] and at faster rates [0.7 (SD 0.5) vs. 0.1 (SD 0.1) μg·ml−1·h−1, P = 0.046] than in survivors. Plasma cytochrome c may represent a novel in vivo marker of mitochondrial injury after resuscitation from cardiac arrest that relates inversely with survival outcome.

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