Energy metabolism response of Litopenaeus vannamei to combined stress of acute cold exposure and waterless duration: Implications for physiological regulation and waterless live transport

Female rats treated chronically with ethynylestradiol (36 micrograms/kg per day) alone, and in combination with the progestational agent, norethynodrel (253 micrograms/kg per day), cooled significantly faster than controls when lightly restrained and exposed to air at 5 degrees C. Rate of cooling of rats given only norethynodrel was similar to that of the control group. In other studies, rate of oxygen consumption was determined for all groups during acute exposure to cold (14 degrees C). All estrogen-treated groups achieved the same maximal rate of oxygen consumption as control and norethynodrel-treated groups during cold exposure, but cooled significantly faster. Two groups of female rats were treated chronically with ethynylestradiol at two separate doses (36 and 61 micrograms/kg per day). An untreated group served as controls. Rate of oxygen consumption of all animals were measured during restraint and exposure to cold (18 degrees C). The estrogen-treated groups again achieved the same maximal rate of oxygen consumption as the control group, but also cooled significantly faster despite the fact that the cold stress was less severe than in the previous experiment. That estrogen-treated rats cooled faster than controls in both studies despite achieving a maximal rate of heat production which did not differ from controls suggests that reduced cold tolerance of estrogen-treated rats may be related to increased heat loss.

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Seasonal variations in the responses of glycolytic intermediates of human erythrocytes to acute cold exposure

International Journal of Biometeorology ◽

10.1007/bf01623995 ◽

1988 ◽

Vol 32 (1) ◽

pp. 52-55

Author(s):

H. Ohno ◽

T. Yahata ◽

K. Yamashita ◽

A. Kuroshima

Keyword(s):

Cold Exposure ◽

Seasonal Variations ◽

Human Erythrocytes ◽

Acute Cold Exposure ◽

Glycolytic Intermediates

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Responses of cold- and warm-adapted dogs to infused norepinephrine and acute body cooling

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1965.209.1.227 ◽

1965 ◽

Vol 209 (1) ◽

pp. 227-230 ◽

Cited By ~ 13

Author(s):

Tetsuo Nagasaka ◽

Loren D. Carlson

Keyword(s):

Heart Rate ◽

Oxygen Consumption ◽

Cold Exposure ◽

Nonshivering Thermogenesis ◽

Mechanically Ventilated ◽

Cold Adapted ◽

Pentobarbital Sodium ◽

Acute Cold Exposure ◽

Increased Sensitivity ◽

Body Cooling

Oxygen consumption, heart rate, and colonic, pinna, and paw temperatures were recorded continuously in warm-adapted (W-A) and cold-adapted (C-A) dogs anesthetized with pentobarbital sodium (30 mg/kg), paralyzed with Flaxedil (5 mg/kg per hr), and mechanically ventilated. The dogs were infused with norepinephrine (1.25 µg/kg per min) for 20 min at 30 C and after 45 min of acute cold exposure to 5 C. Oxygen consumption of C-A dogs increased with a slight increase in the heart rate during the initial 18–20 min of body cooling. O2 consumption decreased continuously during cold exposure in W-A dogs. Calorigenic effects of infused noradrenaline were similar in C-A and W-A dogs at 30 C and 5 C. Heart rate increased in W-A dogs at 30 and 5 C. These results show that nonshivering thermogenesis is well developed by cold acclimation in dogs, and suggest that the increase may be due to an increase in noradrenaline in blood rather than to increased sensitivity of the animals to the calorigenic effects of noradrenaline.

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