Variation in basal metabolic rate and activity in relation to reproductive condition and photoperiod in white-footed mice (Peromyscus leucopus)

2012 ◽  
Vol 90 (5) ◽  
pp. 602-615 ◽  
Author(s):  
P.A. Kaseloo ◽  
M.G. Crowell ◽  
J.J. Jones ◽  
P.D. Heideman

A naturally variable life-history trait with underlying physiological variation is the photoperiodic response of many temperate-zone rodents, including white-footed mice (Peromyscus leucopus (Rafinesque, 1818)). Male P. leucopus were obtained from a short photoperiod responsive (R) line, artificially selected for reproductive suppression in short-day conditions (SD) and a nonresponsive (NR) line selected for reproductive maturity in SD. We tested for variation in metabolic rate between lines in SD and long-day conditions (LD). NR mice consumed 34% more food than R mice, without concomitant increase in body mass in SD. Basal metabolic rate (BMR) was found to be significantly greater in NR than R mice, and NR mice were found to engage in significantly more spontaneous (daily) locomotor activity. Energy-use estimates based on 24 h respirometry matched closely the level of intake reported for individual mice. The increased BMR and average daily metabolic rate in NR mice was correlated with testis size, but not with major central organs or digestibility. No significant difference in BMR or activity was found in mice from the same lines held in LD. Elevated intake in SD mice appears to be associated with differences in fertility and not other aspects of physiology in the respective lines.

Author(s):  
Paweł Brzęk ◽  
Andrzej Gębczyński ◽  
Piotr Selewestruk ◽  
Aneta Książek ◽  
Julita Sadowska ◽  
...  

AbstractThe basal metabolic rate (BMR) accounts for 60–70% of the daily energy expenditure (DEE) in sedentary humans and at least 50% of the DEE in laboratory mice in the thermoneutral zone. Surprisingly, however, the significance of the variation in the BMR is largely overlooked in translational research using such indices as physical activity level (PAL), i.e., the ratio of DEE/BMR. In particular, it is unclear whether emulation of human PAL in mouse models should be carried out within or below the thermoneutral zone. It is also unclear whether physical activity within the thermoneutral zone is limited by the capacity to dissipate heat generated by exercise and obligatory metabolic processes contributing to BMR. We measured PAL and spontaneous physical activity (SPA) in laboratory mice from two lines, divergently selected towards either high or low level of BMR, and acclimated to 30 °C (i.e., the thermoneutral zone), 23 or 4 °C. The mean PAL did not differ between both lines in the mice acclimated to 30 °C but became significantly higher in the low BMR mouse line at the lower ambient temperatures. Acclimation to 30 °C reduced the mean locomotor activity but did not affect the significant difference observed between the selected lines. We conclude that carrying out experiments within the thermoneutral zone can increase the consistency of translational studies aimed at the emulation of human energetics, without affecting the variation in physical activity correlated with BMR.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Marina de Figueiredo Ferreira ◽  
Filipe Detrano ◽  
Gabriela Morgado de Oliveira Coelho ◽  
Maria Elisa Barros ◽  
Regina Serrão Lanzillotti ◽  
...  

Objective.The aim of this study was to determine which of the seven selected equations used to predict basal metabolic rate most accurately estimated the measured basal metabolic rate.Methods.Twenty-eight adult women with type 2 diabetes mellitus participated in this cross-sectional study. Anthropometric and biochemical variables were measured as well as body composition (by absorptiometry dual X-ray emission) and basal metabolic rate (by indirect calorimetry); basal metabolic rate was also estimated by prediction equations.Results.There was a significant difference between the measured and the estimated basal metabolic rate determined by the FAO/WHO/UNU(Pvalue<0.021)and Huang et al.(Pvalue≤0.005)equations.Conclusion.The calculations using Owen et al’s. equation were the closest to the measured basal metabolic rate.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
M Comba

Abstract Background The benefits of providing optimal nutrition for recovery from illness and chronic health management are well documented. The measure of energy expenditure by indirect calorimetry or by predictive equations are two methods to assess energy needs. This abstract provides an overview of indirect calorimetry use in the outpatient setting. The study aims is to compare the results obtained with indirect calorimetry, with those obtained through the theoretical calculation with the Harris-Benedickt formula, by using t-student test. Methods This observational study was conducted from January 2019 to February 2020. The selected population is made up equally of men and women in the general population, from 18 to 65 years of age, without a specific disease, after having given informed consent. Our study was conducted in outpatient setting by using the fitmate pro to do the indirect calorimetry. Results A total of 50 patients were evaluated. The t-student test was used to evaluate whether there was a statistically significant difference in the population analyzed between the basal metabolic rate calculated with the Harris-Benedickt formula and the one measured by indirect calorimetry. The variables evaluated were gender, age (greater than or less than 38 years) BMI (greater than or less than 25). Conclusions A statistically significant results were found (with t-student less than 0.05) for patients over the age of 38 (0.006) and women (0.044). Not statistically significant results were found for the variables: male (0.64), under 38 years of age (0.98), BMI (0.15). Our study shows there are data in favor of the use of indirect calorimetry as a better method for assessing basal metabolic rate instead of Harris-Benedickt for a more targeted approach to the patient. Further studies may support results obtained in this study; furthermore, direct research is necessary in order to increase a personalized approach of the doctor towards the patient. Key messages Our study shows that there are data in favor of the use of indirect calorimetry as a patient-oriented approach to assessing basal metabolic rate. The study aims is to compare the results obtained with indirect calorimetry with those obtained through the theoretical calculation with the Harris-Benedickt formula.


2008 ◽  
Vol 20 (3) ◽  
pp. 431 ◽  
Author(s):  
Roumen Parapanov ◽  
Sébastien Nusslé ◽  
Jacques Hausser ◽  
Peter Vogel

The aim of the present study was to determinate the cycle length of spermatogenesis in three species of shrew, Suncus murinus, Sorex coronatus and Sorex minutus, and to assess the relative influence of variation in basal metabolic rate (BMR) and mating system (level of sperm competition) on the observed rate of spermatogenesis, including data of shrew species studied before (Sorex araneus, Crocidura russula and Neomys fodiens). The dynamics of sperm production were determined by tracing 5-bromodeoxyuridine in the DNA of germ cells. As a continuous scaling of mating systems is not evident, the level of sperm competition was evaluated by the significantly correlated relative testis size (RTS). The cycle durations estimated by linear regression were 14.3 days (RTS 0.3%) in Suncus murinus, 9.0 days (RTS 0.5%) in Sorex coronatus and 8.5 days (RTS 2.8%) in Sorex minutus. In regression and multiple regression analyses including all six studied species of shrew, cycle length was significantly correlated with BMR (r2 = 0.73) and RTS (r2 = 0.77). Sperm competition as an ultimate factor obviously leads to a reduction in the time of spermatogenesis in order to increase sperm production. BMR may act in the same way, independently or as a proximate factor, revealed by the covariation, but other factors (related to testes size and thus to mating system) may also be involved.


1991 ◽  
Vol 81 (3) ◽  
pp. 419-425 ◽  
Author(s):  
M. J. Soares ◽  
L. S. Piers ◽  
P. S. Shetty ◽  
S. Robinson ◽  
A. A. Jackson ◽  
...  

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.


Author(s):  
Bahareh Nikooyeh ◽  
Nastaran Shariatzadeh ◽  
Ali Kalayi ◽  
Maliheh Zahedirad ◽  
Tirang R. Neyestani

Abstract. Some studies have reported inaccuracy of predicting basal metabolic rate (BMR) by using common equations for Asian people. Thus, this study was undertaken to develop new predictive equations for the Iranian community and also to compare their accuracy with the commonly used formulas. Anthropometric measures and thyroid function were evaluated for 267 healthy subjects (18–60 y). Indirect calorimetry (InCal) was performed only for those participants with normal thyroid function tests (n = 252). Comparison of predicted RMR (both kcal/d and kcal.kg.wt−1.d−1) using current predictive formulas and measured RMR revealed that Harris-Benedict and FAO/WHO/UNU significantly over-estimated and Mifflin-St. Jeor significantly under-estimated RMR as compared to InCal measurements. In stepwise regression analysis for developing new equations, the highest r2 (=0.89) was from a model comprising sex, height and weight. However, further analyses revealed that unlike the subjects under 30 y, the association between age and the measured RMR in subjects 30 y and plus was negative (r = −0.241, p = 0.001). As a result, two separate equations were developed for these two age groups. Over 80 percent of variations were covered by the new equations. In conclusion, there were statistical significant under- and over-estimation of RMR using common predictive equations in our subjects. Using the new equations, the accuracy of the calculated RMR increased remarkably.


1976 ◽  
Vol 35 (03) ◽  
pp. 607-619 ◽  
Author(s):  
Allan T. van Oosterom ◽  
Herman Mattie ◽  
Wim Th Hermens ◽  
Jan J. Veltkamp

SummaryThe influence of the thyroid function on the metabolic rate of prothrombin, factor VII, and X was studied in the rat. Disappearance rates of the three coagulation factors were measured after synthesis had been blocked with appropriate doses of warfarin, and reappearance rates were assessed upon induction of synthesis by high doses of vitamin K1 injected into rats displaying coumarin induced hypocoagulability.No statistically significant difference in the disappearance and production rates of any of the factors could be found between normal euthyroid rats and thyroxin-treated hypothyroid rats proven to be euthyroid. The differences between the two euthyroid groups and the hypothyroid group were highly significant, however: hypothyroidism results in an approximately 50% decrease of the metabolic rates of the three coagulation factors under study.The reappearance of the three factors, under euthyroid as well as hypothyroid conditions, showed a biphasic pattern: in the first two hours after vitamin K1 administration to warfarin treated rats, a rapid reappearance was observed, to the same extent for all three factors, in hypo- as well as euthyroid rats. This finding suggests that in vitamin K1 deficiency an intracellular accumulation of precursor proteins (PIVKAs) occurs, which after rapid conversion into biologically active coagulation factors by vitamin K1 are shed into circulation.The subsequent phase of reappearance is much slower and reflects the synthesis rate of coagulation enzymes. It is characteristic for each factor and clearly slower in hypothyroid rats than in euthyroid rats. From this an influence of thyroid function on the synthesis rate of the protein moiety of coagulation factors can be inferred.An apparent difference between disappearance and reappearance rate of the coagulation factors in the plasma, particularly pronounced for factors VII and X in euthyroid rats, could theoretically be explained as the consequence of the model used for derivation of these rates.


1968 ◽  
Vol 57 (4) ◽  
pp. 565-577 ◽  
Author(s):  
K. E. Røkke ◽  
J. H. Vogt

ABSTRACT A report is given on 95 thyrotoxic patients treated with a combination of 400 mg propylthiouracil and 400 mg of potassium perchlorate. Perchlorate was stopped when a marked remission of symptoms was obtained, on an average after less than 7 weeks. Euthyroidism was found on an average after 7.2 weeks. The basal metabolic rate, PBI, plasma total cholesterol and weight showed a fairly rapid normalization. Thirteen of the 95 patients were given radio-iodine therapy shortly before drug therapy was started. The remaining 82 cases were grouped together with the 23 cases previously reported. Of the total of 105 cases, 96 became euthyroid on combined therapy. For the frequency of side-effects, the thirteen cases mentioned above were included, giving a total of 118 cases. Eight cases showed an increase in goitre size and 15 cases had other side-effects, of which three were granulocytopenia due to propylthiouracil. The possibility of a higher frequency of mainly minor side-effects on combined therapy has to be balanced against the seemingly rapid and reliable therapeutic effect. Combined treatment, perhaps with even smaller doses than reported here, can be recommended in selected cases of thyrotoxicosis where a shortening of the thyrotoxic state seems of importance, or possibly where difficulties due to iodine exposure may be anticipated, provided adequate control measures are taken.


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