Whole Body Protein Turnover in Chronically Undernourished Individuals

1994 ◽  
Vol 86 (4) ◽  
pp. 441-446 ◽  
Author(s):  
M. J. Soares ◽  
L. S. Piers ◽  
P. S. Shetty ◽  
A. A. Jackson ◽  
J. C. Waterlow
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Metabolic Rate ◽  
Muscle Mass ◽  
Basal Metabolic Rate ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Whole Body ◽  
Body Protein ◽  
Chronic Undernutrition

1. Two groups of adult men were studied in Bangalore, India, under identical conditions: the ‘normal weight’ subjects (mean body mass index 20.8 kg/m2) were medical students of the institute with access to habitual energy and protein intakes ad libitum. The other group, designated ‘undernourished’, were labourers on daily wages (mean body mass index 16.7 kg/m2). 2. In an earlier study we obtained lower absolute values for both basal metabolic rate and protein synthesis in the undernourished subjects; however, when the data were expressed on a body weight or fat-free mass basis, a trend towards higher rates of protein synthesis, as well as higher basal metabolic rate, was evident. The suggestion was made that such results reflected the relatively higher energy intakes per kg body weight of the undernourished subjects on the day of study. The objective of the present study was therefore to control for the dietary intake during the measurement of whole body protein turnover. 3. In the present study dietary intakes were equated on a body weight basis; however, expressed per kg fat-free mass, the normal weight subjects had received marginally higher intakes of energy and protein. The results, however, were similar to those of the previous study. In absolute terms, basal metabolic rate, protein synthesis and breakdown were lower in the undernourished subjects. When expressed per kg body weight or per kg fat-free mass, the undernourished subjects had higher basal metabolic rates than the well-nourished subjects, whereas no differences were seen in the rate of protein synthesis or breakdown. 4. Estimates of muscle mass, based on creatinine excretion, indicated that the undernourished subjects had a higher proportion of non-muscle to muscle mass. Nitrogen flux (Q) was determined from 15N abundance in two end products, urea (Qu) and ammonia (Qa). The ratio Qu/Qa was increased in the undernourished subjects and was significantly correlated with the ratio of non-muscle to muscle mass (r = 0.81; P < 0.005). These results fit in with our earlier suggestion of a greater proportion of non-muscle (visceral) mass in undernourished subjects. 5. The present data suggest that there are no changes in the rate of protein synthesis or breakdown in chronic undernutrition when results are expressed, conventionally, per kg fat-free mass. It can be theoretically shown, however, that there could be a 15% reduction in the rate of turnover of the visceral tissues in chronic undernutrition. This, together with the reduced urinary nitrogen excretion, would contribute to nitrogen economy in these individuals.

Basal metabolic rate, body composition and whole-body protein turnover in Indian men with differing nutritional status

1991 ◽  
Vol 81 (3) ◽  
pp. 419-425 ◽  
Author(s):  
M. J. Soares ◽  
L. S. Piers ◽  
P. S. Shetty ◽  
S. Robinson ◽  
A. A. Jackson ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Metabolic Rate ◽  
Body Mass ◽  
Basal Metabolic Rate ◽  
Protein Turnover ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Whole Body ◽  
Body Protein ◽  
Significant Difference

1. Three groups of adult men were studied in Bangalore, India: two groups were controls who had been receiving an adequate diet. Of these, one group, designated ‘normal weight controls', had a mean body mass index of 22; the other group, ‘underweight controls', had a mean body mass index of 16.7. The third group consisted of poor labourers, whose daily food intake had been less than 10 MJ and whose mean body mass index was 16.6. Previous studies had shown that such men had a lower basal metabolic rate than well-nourished Indian control subjects. 2. The object of the present study was to find out whether a reduced rate of protein turnover, measured after a single dose of [15N]glycine, contributed to a lower basal metabolic rate. It was found, however, that after adjusting for body weight and fat-free mass by analysis of co-variance there was no significant difference in basal metabolic rate between the three groups. Adjusted rates of protein synthesis were higher in the underweight controls and the undernourished labourers than in the normal weight controls, but not significantly so. 3. Estimates based on creatinine excretion showed that within the fat-free mass the underweight groups had a higher proportion of non-muscle to muscle mass. This may explain the somewhat higher rates of protein turnover in these groups. 4. Nitrogen flux (Q) was determined from 15N abundance in two end products, urea (QU) and ammonia (QA). In the underweight and undernourished groups the ratio QU/QA was increased compared with the normal weight group. This fits in with the finding of a greater proportion of visceral mass in the underweight subjects and with the compartmental model of protein metabolism that we have previously proposed.

scholarly journals The effect of exercise and improved physical fitness on basal metabolic rate

1989 ◽  
Vol 61 (2) ◽  
pp. 155-173 ◽  
Author(s):  
S. A. Bingham ◽  
G. R. Goldberg ◽  
W. A. Coward ◽  
A. M. Prentice ◽  
J. H. Cummings
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Control Period ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Step Test ◽  
Doubly Labelled Water ◽  
Entire Study

1. The suggestion that there is a sustained enhancement in metabolic rate after exercise was investigated during the course of a study in which six normal-weight volunteers (three men, three women) took part in a 9-week training programme. Baseline values were assessed in a 3-5 week control period of minimal activity before training. At the end of the study the subjects were capable of running for I h/d, 5 d/week.2. Throughout the entire study the subjects were maintained on a constant diet. Measurement of energy expenditure by the doubly-labelled water (2H218O) method showed that the subjects had an energy imbalance of +3% in the control and -20% at the end of the training period. The subjects were in positive (1·1 (se 0·2) g) nitrogen balance in the second week of the control, and in negative (-0·6 (se 0·3) g) N balance in the last week of the exercise period.3. Over the course of the study maximum oxygen consumption (Vo2max) and high-density-lipoprotein-cholesterol levels increased by 30%. Heart rate at rest and when performing a standard step test fell significantly.4. Body composition was assessed weekly by40K counting and skinfold thickness measurements, in addition to2H2dilution at the beginning and end of the study. Fat-free mass was apparently gained in the early phases of the study, but there was lack of agreement between the different methods of assessing body composition. Changes in body-weight were not significant.5. Basal metabolic rate (BMR), overnight metabolic rate (OMR) and sleeping metabolic rate (SMR) were measured on three occasions: in the control period, and the beginning and end of the training periods. Average BMR in the control period was 5·91 (se 0·39) MJ/24 h and was not changed with activity. There were no changes in OMR (5·71 (se 0·27) MJ/24 h in the control) nor in SMR (5·18 (se 027) MJ/24 h in the control), nor in BMR, OMR or SMR when expressed per kg body-weight, or per kg fat-free mass.6. These results do not support the suggestion that there is a sustained increase in BMR following exercise that can usefully assist in weight-loss programmes.

A note on the effect of ageing on whole-body protein turn-over in goats

1988 ◽  
Vol 46 (3) ◽  
pp. 479-481 ◽  
Author(s):  
T. Muramatsu ◽  
Y. Ueda ◽  
T. Hirata ◽  
J. Okumura ◽  
I. Tasaki
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Mammalian Species ◽  
Weight Basis ◽  
Dynamic State ◽  
Whole Body ◽  
Body Protein ◽  
Turn Over

In ruminants a dynamic state of protein turn-over has been poorly understood although the methodology of measuring the rate of protein turn-over has recently been advanced to a great extent (Waterlow, Garlick and Millward, 1978). Available evidence suggests that ruminants such as sheep and cows are no exception among various mammalian species when whole-body protein synthesis of adult animals is compared on a metabolic body-weight basis (Waterlow et al., 1978; Reeds and Lobley, 1980).

Aspects of protein metabolism after elective surgery in patients receiving constant nutritional support

1990 ◽  
Vol 78 (6) ◽  
pp. 621-628 ◽  
Author(s):  
F. Carli ◽  
J. Webster ◽  
V. Ramachandra ◽  
M. Pearson ◽  
M. Read ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Metabolic Rate ◽  
Protein Metabolism ◽  
Protein Turnover ◽  
Resting Metabolic Rate ◽  
Plasma Concentrations ◽  
Whole Body ◽  
Body Protein ◽  
Urinary Nitrogen

1. The present study was designed in an attempt to resolve conflicting views currently in the literature relating to the effect of surgery on various aspects of protein metabolism. 2. Sequential post-operative (2, 4 and 6 days) changes in whole-body protein turnover, forearm arteriovenous difference of plasma amino acids, glucose, lactate and free fatty acids, muscle concentration of free amino acids, RNA and protein, urinary nitrogen and 3-methylhistidine, plasma concentrations of insulin, cortisol and growth hormone, and resting metabolic rate, were measured in six patients undergoing uncomplicated elective total abdominal hysterectomy. 3. All patients received a constant daily diet, either orally or intravenously, based on 0.1 g of nitrogen/kg and an energy content of 1.1 times the resting metabolic rate for 7 days before and 6 days after surgery. 4. Whole-body protein turnover, synthesis and breakdown increased significantly 2 days after surgery (P <0.05) and returned towards pre-operative levels thereafter. 5. Forearm release of branched-chain amino acids and alanine, and efflux of glucose and lactate, were enhanced 4 days after surgery (P <0.05). Muscle glutamine and alanine concentrations were decreased on the fourth and sixth days after surgery (P <0.05). The RNA/protein ratio (indicating the capacity for protein synthesis) was unaltered. 6. A significant increase in urinary nitrogen and 3-methylhistidine was observed on days 3 and 4 after surgery (P <0.05). Thereafter, these parameters remained elevated, although failing to reach statistical significance. 7. The resting metabolic rate was significantly increased (P <0.05) 2 days after surgery but the respiratory quotient (0.77) was unchanged. 8. These data support the contention that whole-body protein synthesis and breakdown increase after surgery. Differences observed pre- and post-operatively between leucine kinetic estimates and other methods of quantifying protein metabolism indicate that only like methodologies should be compared.

scholarly journals Response of male and female rats to undernutrition

1984 ◽  
Vol 52 (2) ◽  
pp. 289-306 ◽  
Author(s):  
Patricia M. Harris ◽  
Diane F. Hodgson ◽  
R. B. Broadhurst
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Weight Basis ◽  
Female Rats ◽  
Whole Body ◽  
Synthesis Rate ◽  
Body Protein ◽  
Male And Female ◽  
Fat Depots ◽  
Males And Females

1. In two separate trials male and female Wistar rats, 12 weeks of age, were either killed as a preliminary control group, ad lib.-fed or undernourished for 4 weeks until one-third of their 12-week body-weight was lost.2. Food intakes, urinary and faecal collections and measurements of standard metabolic rate were made at one-weekly intervals on both the ad lib.-fed and undernourished animals of both sexes.3. The bodies of the preliminary controls, the ad lib.-fed and the undernourished animals of both sexes were analysed for protein and fat, and the weights of four fat depots, two muscles and the major organs of all groups were determined.4. Measurements of lipid synthesis rate (LSR) and lipoprotein lipase (EC 3.1.1.34) (LPL) activity in the four fat depots and measurements of whole-body protein synthesis rates were carried out on animals of both sexes in each group.5. Although both sexes lost the same proportion of body-weight the females required more food on a body-weight basis than the males during the undernutrition period. The females absorbed significantly more energy on a body-weight basis during undernutrition and so were less efficient than the males at withstanding nutritional stress.6. There were no significant differences between males and females, on a body-weight basis, in the excretion of nitrogenous waste products (urinary nitrogen, creatinine, hydroxyproline or NT-methylhystidine) suggesting that there were no differences between the sexes in protein sparing during undernutrition.7. There were no differences between males and females in the proportions of body fat and protein used during the period of undernutrition or in the sites of the body from which the protein and fat were mobilized.8. There were no differences between males and females in the way they responded to undernutrition by altering LSR, LPL activity or whole-body protein synthesis rates. Both undernourished males and undernourished females maintained synthesis of lipid, on a per g tissue basis and whole-body protein synthesis at the level found in well-nourished animals of the same sex.

Cardiac output increases independently of basal metabolic rate in early human pregnancy

2000 ◽  
Vol 278 (5) ◽  
pp. H1585-H1588 ◽  
Author(s):  
M. E. A. Spaanderman ◽  
M. Meertens ◽  
M. van Bussel ◽  
T. H. A. Ekhart ◽  
L. L. H. Peeters
Keyword(s):  
Body Weight ◽  
Cardiac Output ◽  
Metabolic Rate ◽  
Early Pregnancy ◽  
Basal Metabolic Rate ◽  
Resting Energy Expenditure ◽  
High Flow ◽  
Fat Free Mass ◽  
Hemodynamic Changes ◽  
Low Resistance

Early pregnancy is characterized by the institution of a high-flow low-resistance circulation. In this study, we tested the hypothesis that these hemodynamic changes develop independently of changes in basal metabolic rate. In 12 healthy women, we determined and calculated once during the follicular phase ( day 5 ± 2) and at 6, 8, 10, and 12 wk of pregnancy the following variables: body weight and length, body mass index, fat-free mass (FFM), mean arterial pressure (MAP), heart rate (HR), stroke volume, cardiac output (CO), total peripheral vascular resistance (TPVR), resting energy expenditure (REE), FFM REE (REEFFM), and respiratory quotient (RQ). At 6 wk of gestational age, HR and CO had increased, whereas MAP and TPVR had decreased. These changes persisted throughout the study period. Meanwhile, REE, REEFFM, RQ, FFM, and body weight did not change consistently. The changes with pregnancy in hemodynamics did not correlate with those in basal metabolic rate. In early pregnancy, the institution of a high-flow low-resistance circulation develops without a concomitant rise in basal metabolic rate. These findings support the concept that the hemodynamic changes in early pregnancy develop independently of concomitant changes in basal metabolic rate.

Effect of testosterone on muscle mass and muscle protein synthesis

1989 ◽  
Vol 66 (1) ◽  
pp. 498-503 ◽  
Author(s):  
R. C. Griggs ◽  
W. Kingston ◽  
R. F. Jozefowicz ◽  
B. E. Herr ◽  
G. Forbes ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Muscle Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Total Body Potassium ◽  
Body Protein ◽  
Total Body

We have studied the effect of a pharmacological dose of testosterone enanthate (3 mg.kg-1.wk-1 for 12 wk) on muscle mass and total-body potassium and on whole-body and muscle protein synthesis in normal male subjects. Muscle mass estimated by creatinine excretion increased in all nine subjects (20% mean increase, P less than 0.02); total body potassium mass estimated by 40K counting increased in all subjects (12% mean increase, P less than 0.0001). In four subjects, a primed continuous infusion protocol with L-[1–13C]leucine was used to determine whole-body leucine flux and oxidation. Whole-body protein synthesis was estimated from nonoxidative flux. Muscle protein synthesis rate was determined by measuring [13C]leucine incorporation into muscle samples obtained by needle biopsy. Testosterone increased muscle protein synthesis in all subjects (27% mean increase, P less than 0.05). Leucine oxidation decreased slightly (17% mean decrease, P less than 0.01), but whole-body protein synthesis did not change significantly. Muscle morphometry showed no significant increase in muscle fiber diameter. These studies suggest that testosterone increases muscle mass by increasing muscle protein synthesis.

Effect of prednisone on protein metabolism in Duchenne dystrophy

1995 ◽  
Vol 268 (1) ◽  
pp. E67-E74 ◽  
Author(s):  
Z. Rifai ◽  
S. Welle ◽  
R. T. Moxley ◽  
M. Lorenson ◽  
R. C. Griggs
Keyword(s):  
Protein Synthesis ◽  
Muscle Mass ◽  
Protein Metabolism ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Duchenne Dystrophy ◽  
Body Protein ◽  
Creatinine Excretion ◽  
Muscle Testing

Prednisone improves strength in Duchenne dystrophy and changes the natural history of the disease. We studied the in vivo effects of prednisone (0.75 mg.kg-1.day-1) on muscle and whole body protein metabolism in six patients with Duchenne dystrophy and three patients with Becker dystrophy. Patients were admitted to the Clinical Research Center for study and consumed a constant flesh-free diet. Strength was measured by manual and quantitative muscle testing. Fractional muscle protein breakdown was estimated by the ratio of 3-methylhistidine to creatinine excretion determined in three consecutive 24-h urine collections. Whole body protein kinetics were studied in the postabsorptive state using a primed continuous infusion of L-[1-13C]leucine. Fractional muscle protein synthesis was determined from tracer incorporation into noncollagen muscle protein obtained by needle biopsy. After 6-8 wk of prednisone treatment, average muscle strength increased by 15% (P < 0.04), and 24-h creatinine excretion (an index of muscle mass) increased by 21% (P = 0.002). 3-Methylhistidine excretion decreased by 10%, but the change was not statistically significant. The ratio of 3-methylhistidine to creatinine excretion decreased by 26% (P < 0.04). Fractional muscle protein synthesis and whole body protein synthesis and breakdown did not change significantly. We conclude that the beneficial effect of prednisone on strength in Duchenne dystrophy appears to be associated with an increase in muscle mass, which may be mediated by inhibition of muscle proteolysis rather than stimulation of muscle protein synthesis.

Resting metabolic rate and protein turnover in apparently healthy elderly Gambian men

1995 ◽  
Vol 268 (6) ◽  
pp. E1083-E1088 ◽  
Author(s):  
C. Benedek ◽  
P. Y. Berclaz ◽  
E. Jequier ◽  
Y. Schutz
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Protein Synthesis ◽  
G Protein ◽  
Protein Turnover ◽  
The Elderly ◽  
Young Group ◽  
Whole Body ◽  
Protein Breakdown ◽  
Body Protein

Body composition, resting energy expenditure (REE), and whole body protein metabolism were studied in 26 young and 28 elderly Gambian men matched for body mass index during the dry season in a rural village in The Gambia. REE was measured by indirect calorimetry (hood system) in the fasting state and after five successive meals. Rates of whole body nitrogen flux, protein synthesis, and protein breakdown were determined in the fed state from the level of isotopic enrichment of urinary ammonia over a period of 12 h after a single oral dose of [15N]glycine. Expressed in absolute value, REE was significantly lower in the elderly compared with the young group (3.21 +/- 0.07 vs. 4.04 +/- 0.07 kJ/min, P < 0.001) and when adjusted to body weight (3.29 +/- 0.05 vs. 3.96 +/- 0.05 kJ/min, P < 0.0001) and fat-free mass (FFM; 3.38 +/- 0.01 vs. 3.87 +/- 0.01 kJ/min, P < 0.0001). The rate of protein synthesis averaged 207 +/- 13 g protein/day in the elderly and 230 +/- 13 g protein/day in the young group, whereas protein breakdown averaged 184 +/- 13 g protein/day in the elderly and 203 +/- 13 g protein/day in the young group (nonsignificant). When values were adjusted for body weight or FFM, they did not reveal any difference between the two groups. It is concluded that the reduced REE adjusted for body composition observed in elderly Gambian men is not explained by a decrease in protein turnover.

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