Scaling the amplitudes of the circadian pattern of resting oxygen consumption, body temperature and heart rate in mammals

2004 ◽  
Vol 139 (1) ◽  
pp. 83-95 ◽  
Author(s):  
Jacopo P. Mortola ◽  
Clement Lanthier
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Circadian Pattern

Body Temperature, Oxygen Consumption, and Heart Rate in Three Species of Australian Flying Foxes

1964 ◽  
Vol 37 (2) ◽  
pp. 179-198 ◽  
Author(s):  
George A. Bartholomew ◽  
Philip Leitner ◽  
John E. Nelson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Flying Foxes

Experimental hyperthyroidism in dogs and effect of salivariectomy

1961 ◽  
Vol 201 (4) ◽  
pp. 723-728 ◽  
Author(s):  
Dorothy A. Piatnek ◽  
Robert E. Olson
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Caloric Intake ◽  
Clinical Signs ◽  
Turnover Rates ◽  
Laboratory Findings ◽  
Thyroid State

A hyperthyroid state was induced and maintained in 17 dogs for 2–10 months by the administration of massive amounts of thyroid hormone. The great tolerance of this species to such large doses was striking. The clinical signs characteristic of hyperthyroidism in other mammals were observed including significantly increased caloric intake, oxygen consumption, heart rate, and body temperature. The laboratory findings included polycythemia, markedly increased levels of protein-bound iodide (PBI), increased turnover rates of l-thyroxine, and a decreased urinary excretion of inorganic iodide. Unlike other species the hyperthyroid dogs did not demonstrate marked reductions in body weight or serum cholesterol. Salivariectomy neither hastened nor enhanced the onset of exogenous hyperthyroidism in the dog. Measurements of the rate of disappearance of I131 l-thyroxine from the plasma and the rate of appearance of radioactive iodide in the urine indicated that the salivary glands in the intact dog are effective sites of deiodination and iodide excretion. This activity, however, is not the sole regulator of the level of circulating thyroid hormone and thus of the thyroid state.

Defending body mass during food restriction in Acomys russatus: a desert rodent that does not store food

2006 ◽  
Vol 290 (4) ◽  
pp. R881-R891 ◽  
Author(s):  
Roee Gutman ◽  
Itzhak Choshniak ◽  
Noga Kronfeld-Schor
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Energy Expenditure ◽  
Body Mass ◽  
Food Restriction ◽  
Daily Torpor ◽  
Spiny Mice ◽  
Desert Rodent ◽  
Initial Decrease

Golden spiny mice, which inhabit rocky deserts and do not store food, must therefore employ physiological means to cope with periods of food shortage. Here we studied the physiological means used by golden spiny mice for conserving energy during food restriction and refeeding and the mechanism by which food consumption may influence thermoregulatory mechanisms and metabolic rate. As comparison, we studied the response to food restriction of another rocky desert rodent, Wagner’s gerbil, which accumulates large seed caches. Ten out of 12 food-restricted spiny mice (resistant) were able to defend their body mass after an initial decrease, as opposed to Wagner’s gerbils ( n = 6). Two of the spiny mice (nonresistant) kept losing weight, and their food restriction was halted. In four resistant and two nonresistant spiny mice, we measured heart rate, body temperature, and oxygen consumption during food restriction. The resistant spiny mice significantly ( P < 0.05) reduced energy expenditure and entered daily torpor. The nonresistant spiny mice did not reduce their energy expenditure. The gerbils’ response to food restriction was similar to that of the nonresistant spiny mice. Resistant spiny mice leptin levels dropped significantly ( n = 6, P < 0.05) after 24 h of food restriction, and continued to decrease throughout food restriction, as did body fat. During refeeding, although the golden spiny mice gained fat, leptin levels were not correlated with body mass ( r2 = 0.014). It is possible that this low correlation allows them to continue eating and accumulate fat when food is plentiful.

Circadian pattern of ventilation during acute and chronic hypercapnia in conscious adult rats

2002 ◽  
Vol 282 (1) ◽  
pp. R244-R251 ◽  
Author(s):  
Erin L. Seifert ◽  
Jacopo P. Mortola
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Ventilatory Response ◽  
Pulmonary Ventilation ◽  
Circadian Pattern ◽  
Adult Rats ◽  
Group Of Seven ◽  
Level Of Activity ◽  
Response Increase ◽  
Flow Through

Because metabolism is a determinant of the ventilatory chemosensitivity, we tested the hypothesis that the ventilatory response to acute and prolonged hypercapnia is adjusted to the circadian oscillations in oxygen consumption (V˙o 2). Adult rats were instrumented for measurements of body temperature (Tb) and activity by telemetry. Pulmonary ventilation (V˙e) was measured by the barometric method and V˙o 2 by the flow-through method. In the acute experiments, 16 conscious rats entrained to a 12:12-h light (L)-dark (D) cycle (lights on 7:00 AM) were exposed to air, 2%, and then 5% CO2 in normoxia (30–45 min each) at 11:00 AM and 11:00 PM. In a separate group of seven rats, simultaneous recordings of all variables were made continuously for 3 consecutive days in air followed by 3 days in 2% CO2 in normoxia, in a 12:12-h L-D cycle (lights on 7:00 AM). In air, all variables were significantly higher at night, whether rats were studied acutely or chronically. Acute CO2exposure had similar significant effects at 11:00 AM and 11:00 PM onV˙e (∼25 and 100% increase with 2 and 5% CO2, respectively) and V˙o 2(∼8% drop with 5% CO2), such that the hyperventilatory response (% increase inV˙e/V˙o 2 from air) was similar at both times. Chronic CO2 breathing increasedV˙e at all times of the day, but less so during the L phase (∼15 vs. 22% increase in L and D, respectively), when activity was lower. However, V˙o 2 was reduced from the air level (∼10% drop) in the L, such that theV˙e/V˙o 2 response was similar between L and D. The same result was obtained when theV˙e/V˙o 2 response was compared between the L and D phases for the same level of activity. These results suggest that, throughout the day, the hypercapnic hyperpnea, whether during acute or prolonged CO2, is perfectly adjusted to the metabolic level.

Body Temperature, Oxygen Consumption, Evaporative Water Loss, and Heart Rate in the Poor-Will

The Condor ◽  
1962 ◽  
Vol 64 (2) ◽  
pp. 117-125 ◽  
Author(s):  
George A. Bartholomew ◽  
Jack W. Hudson ◽  
Thomas R. Howell
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Water Loss ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
The Poor
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