Inverse Relationships between Ecdysteroid Titres and Total Body Metabolism in Insects

In larval and pupal stages of several insect species the changes in total body metabolism appear to be inversely proportional to the course of ecdysteroid titres. The largest peaks of ecdysteroid occur exactly at the time of the lowest metabolic rates. These relationships are consequences of the developmental programming; ecdysteroid has no direct antimetabolic action. The problem of ecdysteroid-metabolic interactions has been discussed in relation to possible homeostatic function of ecdysteroids in insect development.

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Effect of cold exposure on water requirements on three species of small mammals

Journal of Applied Physiology ◽

10.1152/jappl.1977.43.1.121 ◽

1977 ◽

Vol 43 (1) ◽

pp. 121-125 ◽

Cited By ~ 6

Author(s):

D. R. Deavers ◽

J. W. Hudson

Keyword(s):

Body Weight ◽

Turnover Rate ◽

Tritiated Water ◽

Metabolic Rates ◽

Water Requirements ◽

Water Turnover ◽

Blarina Brevicauda ◽

Ad Libitum ◽

Total Body ◽

White Footed Mouse

Water turnover rate (WTR) was determined from tritiated water (3H2O) loss in the short-tailed shrew (Blarina brevicauda), red-backed vole (Clethrionomys gapperi), and white-footed mouse (Peromyscus leucopus). When given ad libitum water at Ta of 20 degrees, B. brevicauda, C. gapperi, and P. leucopus turned over 16.2, 13.8, and 6.2 ml/day, respectively; minimum WTR was 9.9, 7.8, and 3.5 ml/day, respectively. When they were given ad libitum water at 5 degrees C, WTR was 1.4 to 1.6 times higher than at 20 degrees C. On minimum water rations, WTR at 5 degrees C was 1.7 to 1.9 times higher than at 20 degrees C. Since increases in VO2 at 5 degrees C and at 20 degrees C were of about the same magnitude, increased metabolic rates may have caused increased water requirements. Total body water (TBW) was calculated from 3H2O dilution. On minimum water rations, the three species at both Ta's showed decreases in TBW and body weight, but percent body H2O increased.

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A systems-level analysis of dynamic total-body PET data reveals complex skeletal energy metabolism networks in vivo

10.1101/2021.02.16.431368 ◽

2021 ◽

Author(s):

Karla J. Suchacki ◽

Carlos J. Alcaide-Corral ◽

Samah Nimale ◽

Mark G. Macaskill ◽

Roland H. Stimson ◽

...

Keyword(s):

Glucose Metabolism ◽

Metabolic Network ◽

Mineral Metabolism ◽

Integrative Approach ◽

Therapeutic Implications ◽

The Metabolic Syndrome ◽

Metabolic Interactions ◽

Total Body

AbstractBone is now regarded to be a key regulator of a number of metabolic processes, in addition to the regulation of mineral metabolism. However, our understanding of complex bone metabolic interactions at a systems level remains rudimentary, limiting our ability to assess systemic mechanisms underlying diseases and develop novel therapeutics. In vitro molecular biology and bioinformatics approaches have frequently been used to understand the mechanistic changes underlying disease at the cell level, however, these approaches lack the capability to interrogate dynamic multi-bone metabolic interactions in vivo. Here we present a novel and integrative approach to understand complex bone metabolic interactions in vivo using total-body positron emission tomography (PET) network analysis of murine 18F-FDG scans, as a biomarker of glucose metabolism signature in bones. In this report we show that different bones within the skeleton have a unique glucose metabolism and form a complex metabolic network. These data could have important therapeutic implications in the management of the metabolic syndrome and skeletal disease. The application of our approach to clinical and preclinical total-body PET studies promises to reveal further physiological and pathological tissue interactions, which simplistic PET standard uptake values analysis fail to interrogate, extending beyond skeletal metabolism, due to the diversity of PET radiotracers available and under development as well as the advent of clinical total-body PET systems.One Sentence SummaryBones form a complex metabolic network.

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A Systems-Level Analysis of Total-Body PET Data Reveals Complex Skeletal Metabolism Networks in vivo

Frontiers in Medicine ◽

10.3389/fmed.2021.740615 ◽

2021 ◽

Vol 8 ◽

Author(s):

Karla J. Suchacki ◽

Carlos J. Alcaide-Corral ◽

Samah Nimale ◽

Mark G. Macaskill ◽

Roland H. Stimson ◽

...

Keyword(s):

Glucose Metabolism ◽

Mineral Metabolism ◽

Underlying Disease ◽

Integrative Approach ◽

Tissue Interactions ◽

Positron Emission ◽

Metabolic Interactions ◽

Total Body

Bone is now regarded to be a key regulator of a number of metabolic processes, in addition to the regulation of mineral metabolism. However, our understanding of complex bone metabolic interactions at a systems level remains rudimentary. in vitro molecular biology and bioinformatics approaches have frequently been used to understand the mechanistic changes underlying disease at the cell level, however, these approaches lack the capability to interrogate dynamic multi-bone metabolic interactions in vivo. Here we present a novel and integrative approach to understand complex bone metabolic interactions in vivo using total-body positron emission tomography (PET) network analysis of murine 18F-FDG scans, as a biomarker of glucose metabolism in bones. In this report we show that different bones within the skeleton have a unique glucose metabolism and form a complex metabolic network, which could not be identified using single tissue simplistic PET standard uptake values analysis. The application of our approach could reveal new physiological and pathological tissue interactions beyond skeletal metabolism, due to PET radiotracers diversity and the advent of clinical total-body PET systems.

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Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050287 ◽

1974 ◽

Vol 32 ◽

pp. 54-55

Author(s):

S. Phyllis Steamer ◽

Rosemarie L. Devine

Keyword(s):

Structural Changes ◽

Radiation Treatment ◽

Arterial Stenosis ◽

Ultrastructural Changes ◽

Vascular Effects ◽

Microvascular Changes ◽

Surrounding Connective Tissue ◽

Fission Neutrons ◽

Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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The Fine Structure of Irradiated Mouse Heart

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090907 ◽

1976 ◽

Vol 34 ◽

pp. 184-185

Author(s):

Vivian V. Yang ◽

S. Phyllis Stearner

Keyword(s):

Microscopic Level ◽

Ultrastructural Changes ◽

Mouse Heart ◽

Blood Vessel Wall ◽

Histopathological Changes ◽

Light Microscopic Level ◽

Γ Rays ◽

Fission Neutrons ◽

Total Body

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.

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