SEASONAL ADJUSTMENTS IN CAPTURED WILD NORWAY RATS: III. PRODUCTION OF ADRENAL STEROIDS IN VITRO

1963 ◽  
Vol 41 (5) ◽  
pp. 1147-1153 ◽  
Author(s):  
J. S. Willmer ◽  
O. Héroux
Keyword(s):  
Environmental Conditions ◽  
Rattus Norvegicus ◽  
Seasonal Effect ◽  
Seasonal Adjustment ◽  
Adrenal Steroids ◽  
Steroid Secretion ◽  
Adrenal Steroid ◽  
White Rats ◽  
Norway Rats

The in vitro adrenal steroid secretion of wild Norway rats (Rattus norvegicus) captured during the winter differed in quantity, but not in quality, from that of similar rats captured during the summer. Whereas there was no evident seasonal effect on adrenal weight either in males or in females, adrenals of both sexes secreted at a faster rate during the winter than during the summer, this increase involving the four groups of steroids characterized chromatographically during both seasons and in both sexes; the predominant steroid secreted was corticosterone. This seasonal adjustment in adrenal activity is similar to that observed in white rats kept in group cages exposed outdoors to the natural summer and winter environmental conditions, but it differs from that found in white rats cold-acclimated in the laboratory, in which adrenal activity is lower than normal after cold acclimation.

SEASONAL ADJUSTMENTS IN CAPTURED WILD NORWAY RATS: III. PRODUCTION OF ADRENAL STEROIDS IN VITRO

1963 ◽  
Vol 41 (1) ◽  
pp. 1147-1153
Author(s):  
J. S. Willmer ◽  
O. Héroux
Keyword(s):  
Environmental Conditions ◽  
Rattus Norvegicus ◽  
Seasonal Effect ◽  
Seasonal Adjustment ◽  
Adrenal Steroids ◽  
Steroid Secretion ◽  
Adrenal Steroid ◽  
White Rats ◽  
Norway Rats

The in vitro adrenal steroid secretion of wild Norway rats (Rattus norvegicus) captured during the winter differed in quantity, but not in quality, from that of similar rats captured during the summer. Whereas there was no evident seasonal effect on adrenal weight either in males or in females, adrenals of both sexes secreted at a faster rate during the winter than during the summer, this increase involving the four groups of steroids characterized chromatographically during both seasons and in both sexes; the predominant steroid secreted was corticosterone. This seasonal adjustment in adrenal activity is similar to that observed in white rats kept in group cages exposed outdoors to the natural summer and winter environmental conditions, but it differs from that found in white rats cold-acclimated in the laboratory, in which adrenal activity is lower than normal after cold acclimation.

COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: II. SURFACE TEMPERATURE, VASCULARIZATION, AND IN VITRO RESPIRATION OF THE SKIN

1959 ◽  
Vol 37 (1) ◽  
pp. 1247-1253 ◽  
Author(s):  
O. Héroux
Keyword(s):  
Oxygen Uptake ◽  
Surface Temperature ◽  
Respiratory Rate ◽  
Environmental Conditions ◽  
Cold Temperature ◽  
Dorsal Skin ◽  
Adult Rats ◽  
White Rats ◽  
Different Types

The effect of cold temperature on the skin was studied on white rats exposed to two different types of environmental conditions. Two groups of adult rats kept in individual cages were continuously exposed for 3 months to constant cold temperature (18° and 6 °C) in the laboratory (indoor rats) while other groups of the same colony kept in groups of 10 were exposed for the same length of time to the fluctuating environmental conditions prevailing outside (outdoor rats).Indoor rats acclimated to 18 °C and 6 °C showed the same increase in the number of opened capillaries in the ears over the number observed in controls acclimated to 30 °C. "Summer and winter" outdoor rats showed the same number of capillaries as the "18 °C or 6 °C" indoor rats. Signs of injury healing such as thicker epidermis and larger nuclei were found in the ears of all the "6 °C" rats but in none of the "winter" rats. While the skin temperature measured at + 6 °C was slightly higher (0.4 to 1.0 °C) in rats acclimated at 6 °C than in those at 30 °C, it was lower (1.3 to 2.9 °C) in "winter" than in "summer" rats. After 28 days of acclimation, the rate of oxygen uptake of the dorsal skin of the foot was lower in "6 °C" than in "30 °C" rats but after 84 days it was significantly higher in the cold-acclimated rats. Similarly, after 3 months, the respiratory rate of the dorsal skin of the foot was higher in "winter" rats than in "summer" rats.

Prolactin Stimulates and Potentiates Adrenal Steroid Secretion in vitro

1984 ◽  
Vol 20 (4) ◽  
pp. 252-260 ◽  
Author(s):  
Charles Eldridge ◽  
John R. Lymangrover
Keyword(s):  
Steroid Secretion ◽  
Adrenal Steroid

COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: II. SURFACE TEMPERATURE, VASCULARIZATION, AND IN VITRO RESPIRATION OF THE SKIN

1959 ◽  
Vol 37 (11) ◽  
pp. 1247-1253 ◽  
Author(s):  
O. Héroux
Keyword(s):  
Oxygen Uptake ◽  
Surface Temperature ◽  
Respiratory Rate ◽  
Environmental Conditions ◽  
Cold Temperature ◽  
Dorsal Skin ◽  
Adult Rats ◽  
White Rats ◽  
Different Types

The effect of cold temperature on the skin was studied on white rats exposed to two different types of environmental conditions. Two groups of adult rats kept in individual cages were continuously exposed for 3 months to constant cold temperature (18° and 6 °C) in the laboratory (indoor rats) while other groups of the same colony kept in groups of 10 were exposed for the same length of time to the fluctuating environmental conditions prevailing outside (outdoor rats).Indoor rats acclimated to 18 °C and 6 °C showed the same increase in the number of opened capillaries in the ears over the number observed in controls acclimated to 30 °C. "Summer and winter" outdoor rats showed the same number of capillaries as the "18 °C or 6 °C" indoor rats. Signs of injury healing such as thicker epidermis and larger nuclei were found in the ears of all the "6 °C" rats but in none of the "winter" rats. While the skin temperature measured at + 6 °C was slightly higher (0.4 to 1.0 °C) in rats acclimated at 6 °C than in those at 30 °C, it was lower (1.3 to 2.9 °C) in "winter" than in "summer" rats. After 28 days of acclimation, the rate of oxygen uptake of the dorsal skin of the foot was lower in "6 °C" than in "30 °C" rats but after 84 days it was significantly higher in the cold-acclimated rats. Similarly, after 3 months, the respiratory rate of the dorsal skin of the foot was higher in "winter" rats than in "summer" rats.

scholarly journals Acyl-CoA oxidase complexes control the chemical message produced by Caenorhabditis elegans

2015 ◽  
Vol 112 (13) ◽  
pp. 3955-3960 ◽  
Author(s):  
Xinxing Zhang ◽  
Likui Feng ◽  
Satya Chinta ◽  
Prashant Singh ◽  
Yuting Wang ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Environmental Conditions ◽  
Side Chain ◽  
Side Chains ◽  
Activity Assay ◽  
C Elegans ◽  
Substrate Preferences ◽  
Acyl Coa Oxidase ◽  
Coa Thioesters

Caenorhabditis elegans uses ascaroside pheromones to induce development of the stress-resistant dauer larval stage and to coordinate various behaviors. Peroxisomal β-oxidation cycles are required for the biosynthesis of the fatty acid-derived side chains of the ascarosides. Here we show that three acyl-CoA oxidases, which catalyze the first step in these β-oxidation cycles, form different protein homo- and heterodimers with distinct substrate preferences. Mutations in the acyl-CoA oxidase genes acox-1, -2, and -3 led to specific defects in ascaroside production. When the acyl-CoA oxidases were expressed alone or in pairs and purified, the resulting acyl-CoA oxidase homo- and heterodimers displayed different side-chain length preferences in an in vitro activity assay. Specifically, an ACOX-1 homodimer controls the production of ascarosides with side chains with nine or fewer carbons, an ACOX-1/ACOX-3 heterodimer controls the production of those with side chains with seven or fewer carbons, and an ACOX-2 homodimer controls the production of those with ω-side chains with less than five carbons. Our results support a biosynthetic model in which β-oxidation enzymes act directly on the CoA-thioesters of ascaroside biosynthetic precursors. Furthermore, we identify environmental conditions, including high temperature and low food availability, that induce the expression of acox-2 and/or acox-3 and lead to corresponding changes in ascaroside production. Thus, our work uncovers an important mechanism by which C. elegans increases the production of the most potent dauer pheromones, those with the shortest side chains, under specific environmental conditions.

scholarly journals Differential Steroid Secretion and Gonadotropin Response by Individual Tertiary Porcine Follicles in Vitro. Possible Physiologic Role of Atretic Follicles1

1991 ◽  
Vol 44 (3) ◽  
pp. 461-468 ◽  
Author(s):  
Gregor Westhof ◽  
Karin F. Westhof ◽  
Wilhelm L. Braendle ◽  
Gere S. diZerega
Keyword(s):  
Steroid Secretion ◽  
Physiologic Role

Effect of hydrocortisone dose schedule on adrenal steroid secretion in congenital adrenal hyperplasia

1985 ◽  
Vol 106 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Jorg Winterer ◽  
George P. Chrousos ◽  
D. Lynn Loriaux ◽  
Gordon B. Cutler
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
Dose Schedule ◽  
Adrenal Hyperplasia ◽  
Steroid Secretion ◽  
Adrenal Steroid
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