Differential effects of hypoxia on sleep of warm- and cold-acclimated rats

We studied the effect of different levels of hypoxia (10, 12 or 13, 15, and 18% O2) on the sleep-waking pattern (SWP) and the maximum-minimum core temperature of warm-acclimated (WA) and cold-acclimated (CA) rats at their neutral temperature, 29 degrees C. Whereas the SWP of WA rats showed a trend toward increasing disruption as the degree of hypoxia increased, CA rats exhibited no such trend. The effect was chiefly on the frequency of state changes and less on epoch durations. The SWP of WA rats was more vulnerable to hypoxia than that of CA rats. Maximum and minimum body temperatures of WA and CA rats were not significantly affected by O2 lack down to 10% inspired O2. We conclude that in the rat 1) hypoxia primarily affects the neural mechanism that governs the frequency of changes in sleep-waking states; 2) the extent of alterations in SWP's depends on the ambient temperature to which the rats are acclimated; and 3) hypoxia does not significantly affect deep body temperature at the animal's neutral temperature.

Download Full-text

Seasonal and diurnal variations in body temperatures of Hereford and Brahman cross cattle in a cool temperate environment

The Journal of Agricultural Science ◽

10.1017/s0021859600021171 ◽

1970 ◽

Vol 74 (1) ◽

pp. 205-207 ◽

Cited By ~ 5

Author(s):

J. B. Moran

Keyword(s):

Body Temperature ◽

Diurnal Variations ◽

Body Temperatures ◽

East African ◽

Deep Body Temperature ◽

Tropical Regions ◽

Seasonal And Diurnal Variations ◽

Cool Temperate ◽

Temperate Environment ◽

Deep Body

Kendall (1948) suggested that the ability of cattle to thrive in tropical regions could be better indicated by the diurnal variation in body temperature rather than actual body temperature. However, Bligh & Lampkin (1965) found little difference in the nychthemeral variation in deep-body temperature of East African Zebus and Herefords grazing under conditions where the atmospheric shade temperature varied from 71 to 40 °F.

Download Full-text

FEASIBILITY OF USING NEURAL NETWORKS FOR REAL-TIME PREDICTION OF POULTRY DEEP BODY TEMPERATURE RESPONSES TO STRESSFUL CHANGES IN AMBIENT TEMPERATURE

Applied Engineering in Agriculture ◽

10.13031/2013.5139 ◽

2000 ◽

Vol 16 (3) ◽

pp. 303-308 ◽

Cited By ~ 7

Author(s):

B. Lacey ◽

T. K. Hamrita ◽

R. McClendon

Keyword(s):

Neural Networks ◽

Body Temperature ◽

Ambient Temperature ◽

Real Time ◽

Deep Body Temperature ◽

Time Prediction ◽

Temperature Responses ◽

Deep Body

Download Full-text

Sleep-waking pattern and body temperature in hypoxia at selected ambient temperatures

Journal of Applied Physiology ◽

10.1152/jappl.1984.57.5.1564 ◽

1984 ◽

Vol 57 (5) ◽

pp. 1564-1568 ◽

Cited By ~ 9

Author(s):

B. Hale ◽

D. Megirian ◽

M. J. Pollard

Keyword(s):

Body Temperature ◽

Ambient Temperature ◽

Core Temperature ◽

Ambient Temperatures ◽

State Changes ◽

Maximum Minimum ◽

Mild Hypoxia ◽

Low Ambient Temperature

We studied the effect of mild hypoxia (15% O2) and low ambient temperature (Ta = 15 degrees C) on the rat's sleep-waking pattern (SWP) and maximum-minimum core temperature (max-min Tb). Mild hypoxia at neutral Ta (29 degrees C) disrupted the SWP in the same way as low Ta during normoxia: both affected the pattern of frequency of state changes (P less than 0.01), not the pattern of epoch durations. Mild hypoxia and low Ta together caused a degree of disruption of the SWP which was the sum of each alone, i.e., additive. Although both mild hypoxia and low Ta significantly depressed max-min Tb, low Ta exerted a greater effect than mild hypoxia. Together they further depressed max-min Tb in an additive way. We conclude that mild hypoxia disrupts the rat's SWP independent of central thermoregulatory mechanisms at neutral Ta, that the effects of mild hypoxia and low Ta on the SWP are additive at the stimulus levels used, and that Ta, not inspired O2, determines Tb.

Download Full-text

ASSESSMENT OF POULTRY DEEP BODY TEMPERATURE RESPONSES TO AMBIENT TEMPERATURE AND RELATIVE HUMIDITY USING AN ON-LINE TELEMETRY SYSTEM

Transactions of the ASAE ◽

10.13031/2013.2754 ◽

2000 ◽

Vol 43 (3) ◽

pp. 717-721 ◽

Cited By ~ 7

Author(s):

B. Lacey ◽

T. K. Hamrita ◽

M. P. Lacy ◽

G. L. Van Wicklen

Keyword(s):

Body Temperature ◽

Relative Humidity ◽

Ambient Temperature ◽

Telemetry System ◽

Deep Body Temperature ◽

On Line ◽

Temperature Responses ◽

Deep Body

Download Full-text

First order dynamics approaching of broiler chicken deep body temperature response to step changes in ambient temperature

International Journal of Agricultural and Biological Engineering ◽

10.25165/j.ijabe.20171004.2336 ◽

2017 ◽

Vol 10 (4) ◽

pp. 13-21 ◽

Cited By ~ 1

Author(s):

Takoi K. Hamrita ◽

◽

Richard H. Conway ◽

Keyword(s):

Body Temperature ◽

Ambient Temperature ◽

Broiler Chicken ◽

Temperature Response ◽

Deep Body Temperature ◽

First Order ◽

Deep Body

Download Full-text

Physiological conflict in humans: fatigue vs. cold discomfort

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1983.244.5.r621 ◽

1983 ◽

Vol 244 (5) ◽

pp. R621-R628 ◽

Cited By ~ 2

Author(s):

M. Cabanac ◽

J. Leblanc

Keyword(s):

Heart Rate ◽

Body Temperature ◽

Ambient Temperature ◽

Human Subjects ◽

Climatic Chamber ◽

Deep Body Temperature ◽

Deep Body

Six male human subjects were placed in a situation of physiological conflict, fatigue vs. cold discomfort. Dressed in swim suits and shoes they walked at 3 km X h-1 on a treadmill placed in a climatic chamber. The slope of the treadmill was varied from 0 to 24% and the ambient temperature (Ta) from 25 to 5 degrees C. The subjects could choose Ta when slope was imposed or the converse. They rated pleasure and displeasure of Ta and exercise. Deep body temperature and heart rate were monitored. The results show that the subjects adjusted their behavior to maintain approximatively steady deep body temperature and to limit heart rate below 120 beats X min-1. The physiological compromise was thus correlated to the drive for maximal pleasure-minimal displeasure in the two sensory dimensions fatigue and discomfort.

Download Full-text

Induced hyperthermia in sedated humans and the concept of critical thermal maximum

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1978.235.5.r228 ◽

1978 ◽

Vol 235 (5) ◽

pp. R228-R236 ◽

Cited By ~ 24

Author(s):

G. D. Bynum ◽

K. B. Pandolf ◽

W. H. Schuette ◽

R. F. Goldman ◽

D. E. Lees ◽

...

Keyword(s):

Body Temperature ◽

Exposure Time ◽

Serum Enzymes ◽

Critical Thermal Maximum ◽

Body Temperatures ◽

Mathematical Technique ◽

Deep Body Temperature ◽

Equivalent Time ◽

Thermal Maximum ◽

Deep Body

The concept of critical thermal maximum (CTM) has been defined in the literature as the minimal high deep-body temperature that is lethal to an animal. In man the CTM has been estimated at 41.6--42.0 degrees C. Data are presented for sedated, unacclimatized, well-hydrated men heated 1 h at esophageal temperatures of 41.6--42.0 degrees C, without sequelae, except for modest elevation of serum enzymes in two of five patients. These data when combined with other observations in the literature suggest that CTM be redefined as the particular combination of exposure time at elevated body temperatures that results in either subclinical (CTM)s) or clinical (CTMc) injuries. Also presented is a mathematical technique, equivalent time at 42 degrees C (Teq 42 degrees), for expressing hyperthermia in terms of body temperature and exposure time.

Download Full-text

Evaluation of a newly developed monitor of deep body temperature

Journal of Anesthesia ◽

10.1007/s005400200056 ◽

2002 ◽

Vol 16 (4) ◽

pp. 354-357 ◽

Cited By ~ 21

Author(s):

Michiaki Yamakage ◽

Sohshi Iwasaki ◽

Akiyoshi Namiki

Keyword(s):

Body Temperature ◽

Deep Body Temperature ◽

Deep Body

Download Full-text

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

Canadian Journal of Zoology ◽

10.1139/z91-254 ◽

1991 ◽

Vol 69 (7) ◽

pp. 1842-1847 ◽

Cited By ~ 5

Author(s):

Gregory K. Snyder ◽

Joseph R. Coelho ◽

Dalan R. Jensen

Keyword(s):

Oxygen Consumption ◽

Thyroid Hormone ◽

Body Temperature ◽

Ambient Temperature ◽

Cold Exposure ◽

Elevated Serum ◽

Body Temperatures ◽

Serum Thyroid Hormone ◽

Regulate Body Temperature ◽

Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

Download Full-text