Some seasonal changes in Antechinus flavipes (Marsupialia : Dayuridae)

1976 ◽  
Vol 24 (4) ◽  
pp. 523 ◽  
Author(s):  
RW Inns
Keyword(s):  
Body Weight ◽  
Energy Consumption ◽  
Energy Loss ◽  
Metabolic Rate ◽  
Seasonal Changes ◽  
Hormonal Changes ◽  
Male Mortality ◽  
Males And Females ◽  
Normal Males ◽  
Hormone System

Seasonal changes in some basic bioenergetic functions were investigated in the marsupial mouse A. flavipes by comparing normal males with females and castrated males. The activity and body weight of intact males increased to a peak in late June, at the same time metabolic rate increased. After the period of maximum testis development from late June to the end of July the activity of males declined, as did body weight and scrota1 width. The pelage of intact males also deteriorated, while the female and castrated males remained sleek and maintained weight. The metabolic rate of intact males also declined after the breeding season, whereas that of the castrated males remained constant. Despite a decline in body weight, intact males showed an increase in energy consumption in July which remained high in August and September; faecal energy loss was lower in September than July. Energy consumption in castrated males did not increase until September, faecal energy loss did not change during the year. The differences observed among intact males, castrated males and females suggests that the male sex hormone system influences the metabolic and hormonal changes associated with male mortality.

Regulation of metabolic rate in Svalbard and Norwegian reindeer

1984 ◽  
Vol 247 (5) ◽  
pp. R837-R841 ◽  
Author(s):  
K. J. Nilssen ◽  
J. A. Sundsfjord ◽  
A. S. Blix
Keyword(s):  
Body Weight ◽  
Critical Temperature ◽  
Food Intake ◽  
Metabolic Rate ◽  
Seasonal Changes ◽  
Serum Levels ◽  
Physiological Adaptation ◽  
Conservation Of Energy ◽  
Winter Food ◽  
Lower Critical Temperature

Food intake, body weight, serum levels of triiodothyronine (T3) and free thyroxine (FT4), and metabolic rate were measured at intervals in Svalbard (SR) and Norwegian (NR) reindeer. From summer to winter food intake decreased 57 (SR) and 55% (NR), while body weight decreased 8.6 (SR) and 3.8% (NR). In SR T3 and FT4 changed seasonally, whereas this was only evident for T3 in NR. Resting (standing) metabolic rate (RMR) in winter was 1.55 (SR) and 2.05 W X kg-1 (NR), lower critical temperature (TLC) being -50 (SR) and -30 degrees C (NR). RMR in summer was 2.15 (SR) and 2.95 W X kg-1 (NR), TLC being -15 (SR) and 0 degrees C (NR). Seasonal changes in T3 and FT4 did not coincide with changes in food intake or RMR in either SR or NR. RMR did, however, correlate with food intake. This indicates that seasonal changes in RMR are due to the thermic effects of feeding and represent no physiological adaptation aimed at conservation of energy during winter.

Energetics of bipedal running. I. Metabolic cost of generating force.

1998 ◽  
Vol 201 (19) ◽  
pp. 2745-2751 ◽  
Author(s):  
T J Roberts ◽  
R Kram ◽  
P G Weyand ◽  
C R Taylor
Keyword(s):  
Body Weight ◽  
Energy Consumption ◽  
Metabolic Rate ◽  
Body Mass ◽  
Energy Use ◽  
Force Production ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Force Generation ◽  
Running Mechanics

Similarly sized bipeds and quadrupeds use nearly the same amount of metabolic energy to run, despite dramatic differences in morphology and running mechanics. It has been shown that the rate of metabolic energy use in quadrupedal runners and bipedal hoppers can be predicted from just body weight and the time available to generate force as indicated by the duration of foot-ground contact. We tested whether this link between running mechanics and energetics also applies to running bipeds. We measured rates of energy consumption and times of foot contact for humans (mean body mass 78.88 kg) and five species of birds (mean body mass range 0.13-40.1 kg). We find that most (70-90%) of the increase in metabolic rate with speed in running bipeds can be explained by changes in the time available to generate force. The rate of force generation also explains differences in metabolic rate over the size range of birds measured. However, for a given rate of force generation, birds use on average 1.7 times more metabolic energy than quadrupeds. The rate of energy consumption for a given rate of force generation for humans is intermediate between that of birds and quadrupeds. These results support the idea that the cost of muscular force production determines the energy cost of running and suggest that bipedal runners use more energy for a given rate of force production because they require a greater volume of muscle to support their body weight.

INFLUENCE OF METYRAPONE ON PLASMA CONCENTRATIONS OF TESTOSTERONE AND ANDROSTENEDIONE IN MAN

1971 ◽  
Vol 68 (3) ◽  
pp. 576-584 ◽  
Author(s):  
K. O. Nilsson ◽  
B. Hökfelt
Keyword(s):  
Body Weight ◽  
Male Patient ◽  
Gradual Increase ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Normal Males ◽  
A Minor ◽  
Secondary Hypogonadism

ABSTRACT Metyrapone was administered either orally, 750 mg every four h, in a total of six doses, or intravenously 30 mg per kg body weight as a four h infusion. In three males with normal endocrine functions, metyrapone given orally or intravenously induced a fall in plasma testosterone and an elevation of androstenedione within 2–8 h. When metyrapone was administered to a patient given dexamethasone to suppress endogenous ACTH production, the androstenedione levels did not alter whereas the testosterone levels showed a slight, transient decrease. In two normal females metyrapone administration was followed by a marked increase in plasma androstenedione whereas testosterone showed only a minor, gradual increase. In one male patient with Addison's disease the basal plasma testosterone was normal whereas the level of androstenedione was low. Following metyrapone intravenously, there was a slight suppression of plasma testosterone but no change in the androstenedione concentration. In one patient with primary hypogonadism, two with secondary hypogonadism and two with Klinefelter's syndrome the plasma testosterone was low under basal conditions and did not change following metyrapone. Basal plasma androstenedione was within the range for normal males and increased markedly following metyrapone in all the cases.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS:

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson
Keyword(s):  
Ascorbic Acid ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Female Rat ◽  
Feedback Effects ◽  
Male And Female ◽  
Prostate Weight ◽  
Male And Female Rats ◽  
Males And Females ◽  
Normal Males

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.

Lethal mutations in Euphydryas aurinea beckeri (Lederer, 1853) (Lepidoptera: Nymphalidae) from Sierra Blanca, Malaga, Spain

2019 ◽  
Vol 70 (4) ◽  
pp. 211-216
Author(s):  
Jim Pateman ◽  
Peter Russell
Keyword(s):  
The Other ◽  
Lethal Mutations ◽  
Males And Females ◽  
Normal Males

Two Euphydryas aurinea beckeri females from Sierra Blanca, Malaga, Spain were captured and returned to the U.K.; each laid a single egg batch on Succisa pratensis. Both batches hatched and the resulting larvae were reared through to adulthood. One group of larvae produced butterflies with three different mutations: pupae with spines, legs lacking distal tarsals and claws, and with appendages attached to the genitalia which protruded though the rear of the abdomens in both males and females. The other group of larvae produced normal males and females.

Some consequences of body size

1984 ◽  
Vol 247 (4) ◽  
pp. H495-H507 ◽  
Author(s):  
L. E. Ford
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Metabolic Rate ◽  
Muscle Power ◽  
Weight Ratio ◽  
Single Species ◽  
Hill Climbing ◽  
Proper Size ◽  
Higher Power ◽  
Metabolic Indices

The question of the proper size denominator for metabolic indices is addressed. Metabolic rate among different species is proportional to the 3/4 power of body weight, not surface area. Muscle power also varies with the 3/4 power of weight, suggesting that metabolic rate is determined mainly by muscle power. Power-to-weight ratio, specific metabolic rate, and a number of metabolic periods, including heart rate, all vary inversely with the 1/4 power of body weight. Thus the relative times required for physiological and pathological processes in different species may be estimated from the average resting heart rate for the species. There are not many small humans among athletic record holders in events involving acceleration and hill climbing, as would be expected if they had higher power-to-weight ratios. Thus the relationship between size and metabolic rate in different species should not be applied within the single species of humans. Evidence is reviewed showing that basal metabolic rate in humans is determined mainly by lean body mass.

scholarly journals Interrelationships of body weight and bone weight with densitometric properties of tibiotarsal bone in geese during post-hatching development

2017 ◽  
Vol 60 (No. 12) ◽  
pp. 682-690
Author(s):  
A. Charuta ◽  
MR Tatara ◽  
M. Dzierzecka ◽  
E. Polawska ◽  
I. Ptaszynska-Sarosiek
Keyword(s):  
Computed Tomography ◽  
Body Weight ◽  
Correlation Coefficient ◽  
Quantitative Computed Tomography ◽  
Peripheral Quantitative Computed Tomography ◽  
Dual Energy ◽  
X Ray ◽  
Males And Females ◽  
Different Parts

The aim of this study was to evaluate interrelationships of body weight and bone weight and densitometric properties of the tibiotarsus in White Koluda Geese (W31) in the post-hatching period. The study was performed using dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT) at two different parts of tibia: proximal metaphysis and mid-diaphysis. The investigation was performed on 100 bones obtained from males and females at the age of 1, 14, 28, 42 and 56 days of life. All the calculations were performed using the Statistica 9.0 software (StatSoft, Inc. Tulsa, USA). Pearson’s correlation coefficient of body weight and bone weight with all the investigated variables of bone was determined. Depending on the method used for densitometric measurements – DEXA or pQCT, the current study has revealed significant differences in the number of correlations of bone weight and body weight with the evaluated densitometric parameters. Sex-related differences in the investigated interrelationships were also found. In the case of proximal epiphysis, negative correlations of vBMD, tBMC, CTR_DEN and CRT_CNT with body weight and bone weight dominated in one-day-old males. Based on the current observations and the negative correlations of body weight and vBMD, CRT_DEN and TRAB_DEN obtained in the mid-diaphysis of tibiotarsus at the age of 14 days of life, it was concluded that this bone is much more prone to deformations and fractures in males than in females.

Respiratory Exchange and Body Size in the Aldabra Giant Tortoise

1971 ◽  
Vol 55 (3) ◽  
pp. 651-665 ◽  
Author(s):  
G. M. HUGHES ◽  
R. GAYMER ◽  
MARGARET MOORE ◽  
A. J. WOAKES
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Metabolic Rate ◽  
Relative Proportion ◽  
The Body ◽  
O2 Consumption ◽  
Weight Range ◽  
Testudo Hermanni ◽  
The Mean ◽  
Good Agreement

1. The O2 consumption and CO2 release of nine giant tortoises Testudo gigantea (weight range 118 g-35·5 kg) were measured at a temperature of about 25·5°C. Four European tortoises Testudo hermanni (weight range 640 g-2·16 kg) were also used. The mean RQ values obtained were 1·01 for T. gigantea and 0·97 for T. hermanni. These values were not influenced by activity or size. 2. The data was analysed by plotting log/log regression lines relating body weight to O2 consumption. Both maximum and minimum metabolic rates recorded for each individual T. gigantea showed a negative correlation with body weight. For active rates the relation was O2 consumption = 140·8W0·97, whereas for inactive animals O2 consumption = 45·47W0·82. 3. The maximum rates were obtained from animals that were observed to be active in the respirometer and the minimum rates from animals that remained quiet throughout. The scope for activity increased with body size, being 82 ml/kg/h for animals of 100 g and 103 ml/kg/h for 100 kg animals. The corresponding ratio between maximum and minimum rates increases from about 2 to 6 for the same weight range. 4. Values for metabolic rate in T. hermanni seem to be rather lower than in T. gigantea. Analysis of the relative proportion of the shell and other organs indicates that the shell forms about 31% of the body weight in adult T. hermanni but only about 18% in T. gigantea of similar size. The shell is not appreciably heavier in adult T. gigantea (about 20%). 5. Data obtained for inactive animals is in good agreement with results of other workers using lizards and snakes. Previous evidence suggesting that chelonians show no reduction in metabolic rate with increasing size is not considered to conflict with data obtained in the present work.

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