scholarly journals Continued artificial selection for running endurance in rats is associated with improved lung function

2009 ◽  
Vol 106 (6) ◽  
pp. 1810-1818 ◽  
Author(s):  
Scott D. Kirkton ◽  
Richard A. Howlett ◽  
Norberto C. Gonzalez ◽  
Patrick G. Giuliano ◽  
Steven L. Britton ◽  
...  
Keyword(s):  
Body Size ◽  
Lung Volume ◽  
Maximal Oxygen Consumption ◽  
Endurance Capacity ◽  
Endurance Running ◽  
Body Frame ◽  
Cardiopulmonary Function ◽  
Muscle Adaptations ◽  
Selection For ◽  
Seven Generations

Previous studies found that selection for endurance running in untrained rats produced distinct high (HCR) and low (LCR) capacity runners. Furthermore, despite weighing 14% less, 7th generation HCR rats achieved the same absolute maximal oxygen consumption (V̇o2max) as LCR due to muscle adaptations that improved oxygen extraction and use. However, there were no differences in cardiopulmonary function after seven generations of selection. If selection for increased endurance capacity continued, we hypothesized that due to the serial nature of oxygen delivery enhanced cardiopulmonary function would be required. In the present study, generation 15 rats selected for high and low endurance running capacity showed differences in pulmonary function. HCR, now 25% lighter than LCR, reached a 12% higher absolute V̇o2max than LCR, P < 0.05 (49% higher V̇o2max/kg). Despite the 25% difference in body size, both lung volume (at 20 cmH2O airway pressure) and exercise diffusing capacity were similar in HCR and LCR. Lung volume of LCR lay on published mammalian allometrical relationships while that of HCR lay above that line. Alveolar ventilation at V̇o2max was 30% higher, P < 0.05 (78% higher, per kg), arterial Pco2 was 4.5 mmHg (17%) lower, P < 0.05, while total pulmonary vascular resistance was (insignificantly) 5% lower (30% lower, per kg) in HCR. The smaller mass of HCR animals was due mostly to a smaller body frame rather than to a lower fat mass. These findings show that by generation 15, lung size in smaller HCR rats is not reduced in concert with their smaller body size, but has remained similar to that of LCR, supporting the hypothesis that continued selection for increased endurance capacity requires relatively larger lungs, supporting greater ventilation, gas exchange, and pulmonary vascular conductance.

scholarly journals Atmospheric Hypoxia Limits Selection for Large Body Size in Insects

PLoS ONE ◽  
2009 ◽  
Vol 4 (1) ◽  
pp. e3876 ◽  
Author(s):  
C. Jaco Klok ◽  
Jon F. Harrison
Keyword(s):  
Body Size ◽  
Large Body ◽  
Large Body Size ◽  
Selection For

RESPONSE TO SELECTION FOR BODY WEIGHT OR FEED EFFICIENCY IN MICE TESTED ON CORN, RYE AND WHEAT DIETS

1986 ◽  
Vol 66 (2) ◽  
pp. 389-397
Author(s):  
R. I. McKAY ◽  
R. J. PARKER ◽  
W. GUENTER
Keyword(s):  
Body Weight ◽  
Feed Efficiency ◽  
Mass Selection ◽  
Response To Selection ◽  
Initial Weight ◽  
Commercial Diet ◽  
Final Weight ◽  
Dc Line ◽  
Selection For ◽  
Seven Generations

Mass selection for adjusted feed efficiency (AFE, g gain/g feed) and adjusted body weight (ABW, g) of male mice was practiced for seven generations on each of three diets: corn, rye and wheat. The three experimental diets, fed between 21 and 35 d, were isocaloric (approximately 16.5 MJ GE kg−1) and isonitrogenous (CP approximately 13%). A common commerical diet (PC) was fed at all other times. With each diet two control lines, randomly mated, were tested on either the experimental diets (DC) or a commercial diet (PC). Selection was based upon linear adjustment to a common initial weight (10 g) for either final weight (ABW) or feed efficiency (AFE) measured between 21 and 35 d of age. Response was determined as a deviation from the appropriate DC line. All animals were placed in specially designed individual cages during the test period. Half-sib estimates of heritability in the PC line were 0.13(± 0.11) for ABW and 0.19(± 0.10) for AFE. Half-sib estimates pooled across lines and diets were 0.16(± 0.07) for ABW and 0.28(± 0.07) for AFE. Realized heritabilities for ABW were 0.24(± 0.06), 0.06(± 0.07) and 0.14(± 0.06) for the corn, rye and wheat diets, respectively. Response to selection for AFE was poor with the highest heritability obtained on the wheat diet (h2 = 0.13 ± 0.02). Key words: Selection, mice, body weight, feed efficiency, diets

Metacarpals and manual phalanges

2020 ◽  
pp. 106-143
Author(s):  
Tracy L. Kivell ◽  
Kelly R. Ostrofsky ◽  
Brian G. Richmond ◽  
Michelle S.M. Drapeau
Keyword(s):  
Body Size ◽  
South African ◽  
Index Finger ◽  
External Morphology ◽  
Australopithecus Africanus ◽  
Fossil Evidence ◽  
Frequent Use ◽  
Selection For ◽  
Locomotor Behaviors ◽  
Fossil Hominin

This chapter presents description and analysis of the metacarpals and manual phalanges from Sterkfontein. Although the morphology is generally similar across the sample where there are duplicates of the same element, there are differences in size that are quite remarkable within the context of all South African hominins. Some very large specimens suggest the presence of individuals at Sterkfontein with much larger hands, and presumably larger body size, at Sterkfontein than those of A. sediba MH2, H. naledi and the Swartkrans hominins. Australopithecus africanus had human-like proportions, but this may be plesiomorphic within the hominoid clade. The potentially less mobile trapezium-Mc1 joint, absence of a fully developed palmar pulp on the distal thumb, more limited pronation of the index finger, and potentially more wedge-shaped trapezoid inferred from the preserved external morphology, is consistent with lower manipulative loading of the thumb than is typical of later Homo. As for other forelimb elements, moderately curved manual phalanges suggests a greater reliance on forelimb-dominated locomotor behaviors and perhaps selection for more frequent use of an arboreal environment in A. africanus than is found in A. afarensis. Thus, within this broader context, the Sterkfontein fossil hominin remains are not unusual. The Sterkfontein hand fossils suggest an overall manipulative and locomotor loading regime that was more similar to that of other South African australopiths and distinct from that of later Homo, but more refined functional interpretations require additional fossil evidence, particularly from associated hand skeletons

Relationship between lung volume and tracheal area as assessed by acoustic reflection

1988 ◽  
Vol 64 (3) ◽  
pp. 1050-1054 ◽  
Author(s):  
L. J. Brooks ◽  
P. J. Byard ◽  
R. C. Helms ◽  
J. M. Fouke ◽  
K. P. Strohl
Keyword(s):  
Young Adults ◽  
Body Size ◽  
Lung Disease ◽  
Lung Volume ◽  
Vital Capacity ◽  
Significant Positive Correlation ◽  
Lung Parenchyma ◽  
Sectional Area ◽  
Cross Sectional ◽  
Acoustic Reflection

To determine whether airway size correlates with measures of lung or body size, we used the acoustic reflection technique to calculate tracheal cross-sectional area in 103 healthy young adults. Men have significantly larger tracheas than women [2.48 ± 0.08 vs. 1.91 ± 0.05 (SE) cm2, P less than 0.001]. Within each sex, there is no correlation between tracheal size and body size or maximal expiratory flows. There is a significant positive correlation between tracheal area and vital capacity in males only (r = 0.36, P less than 0.01). These results support the concept of dysanapsis, relatively independent growth of the airways and lung parenchyma, as well as sex-related differences in airway size and growth. Inherent airway size may be a factor in the development and/or progression of lung disease.

scholarly journals Patient Selection for Bronchoscopic Lung Volume Reduction

2020 ◽  
Vol Volume 15 ◽  
pp. 871-881 ◽  
Author(s):  
Jorrit BA Welling ◽  
Jorine E Hartman ◽  
Sonja WS Augustijn ◽  
Huib AM Kerstjens ◽  
Lowie EGW Vanfleteren ◽  
...  
Keyword(s):  
Patient Selection ◽  
Lung Volume ◽  
Volume Reduction ◽  
Lung Volume Reduction ◽  
Selection For

scholarly journals Selection for small body size favours contrasting sex-specific life histories, boldness and feeding in medaka, Oryzias latipes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Beatriz Diaz Pauli ◽  
Sarah Garric ◽  
Charlotte Evangelista ◽  
L. Asbjørn Vøllestad ◽  
Eric Edeline
Keyword(s):  
Body Size ◽  
Life Histories ◽  
Small Body ◽  
Oryzias Latipes ◽  
Small Body Size ◽  
Selection For

scholarly journals Pterostilbene Enhances Endurance Capacity via Promoting Skeletal Muscle Adaptations to Exercise Training in Rats

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 186 ◽  
Author(s):  
Jiawei Zheng ◽  
Wujian Liu ◽  
Xiaohui Zhu ◽  
Li Ran ◽  
Hedong Lang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Mitochondrial Biogenesis ◽  
C2c12 Myotubes ◽  
Endurance Capacity ◽  
Muscle Adaptations ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Skeletal Muscle Adaptations

It has been demonstrated that skeletal muscle adaptions, including muscle fibers transition, angiogenesis, and mitochondrial biogenesis are involved in the regular exercise-induced improvement of endurance capacity and metabolic status. Herein, we investigated the effects of pterostilbene (PST) supplementation on skeletal muscle adaptations to exercise training in rats. Six-week-old male Sprague Dawley rats were randomly divided into a sedentary control group (Sed), an exercise training group (Ex), and exercise training combined with 50 mg/kg PST (Ex + PST) treatment group. After 4 weeks of intervention, an exhaustive running test was performed, and muscle fiber type transformation, angiogenesis, and mitochondrial content in the soleus muscle were measured. Additionally, the effects of PST on muscle fiber transformation, paracrine regulation of angiogenesis, and mitochondrial function were tested in vitro using C2C12 myotubes. In vivo study showed that exercise training resulted in significant increases in time-to-exhaustion, the proportion of slow-twitch fibers, muscular angiogenesis, and mitochondrial biogenesis in rats, and these effects induced by exercise training could be augmented by PST supplementation. Moreover, the in vitro study showed that PST treatment remarkably promoted slow-twitch fibers formation, angiogenic factor expression, and mitochondrial function in C2C12 myotubes. Collectively, our results suggest that PST promotes skeletal muscle adaptations to exercise training thereby enhancing the endurance capacity.

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