The effects of acute cold exposure on morphology and gene expression in the heart of neonatal chicks

2016 ◽  
Vol 186 (3) ◽  
pp. 363-372
Author(s):  
Tomoko Matsubara ◽  
Saki Shimamoto ◽  
Daichi Ijiri ◽  
Akira Ohtsuka ◽  
Yukio Kanai ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cold Exposure ◽  
Acute Cold Exposure ◽  
Neonatal Chicks

scholarly journals Blunted Expression of PPARa in Mice with FABP-4 and -5 Deficiency under Acute Cold Exposure

2017 ◽  
Vol 3 (6) ◽  
pp. 443
Author(s):  
Mas Rizky A.A Syamsunarno ◽  
Mirasari Putri ◽  
Tatsuya Iso ◽  
Rini Widyastuti ◽  
Ramdan Panigoro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Uncoupling Protein ◽  
Nuclear Hormone Receptor ◽  
Fatty Acid Binding ◽  
Acute Cold Exposure ◽  
Brown Adipose

Brown Adipose Tissue (BAT) is a nonshivering thermogenesis organ during cold exposure. Peroxisomal proliferator activated receptor alpha (PPARa) is the member of the nuclear hormone receptor superfamily and primarily expressed in BAT and liver. PPARa is coordinated with uncoupling protein 1 (UCP1) to regulate fatty acid metabolism in BAT. Fatty acid binding protein (FABP)-4 and-5 play role in adaptive response under fasting and cold exposure. The purpose of this study was to investigate the expression of PPARa in mice with FABP4/5 deficiency (DKO). Wildtype (WT) and DKO mice were exposed to cold for 2 hours under fed or 20 hours-fasted conditions. BAT was collected and further mRNA level of PPARa was examined using quantitative real-time PCR. As the result, PPARa gene expression in WT mice were increased 50% and 100% in fed and fasted condition respectively after cold exposure. There was no alteration in PPARa expression in  BAT of DKO mice. As conclusion, The functional FABP-4 and -5 are necessary to modulate PPARa gene expression in Brown Adipose Tissue under acute cold exposure  Keywords: Acute cold exposure; FABP4; FABP5; Fasting  PPARa

Tolerance of estrogen-treated rats to acute cold exposure

1979 ◽  
Vol 47 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M. J. Fregly ◽  
D. L. Kelleher ◽  
D. J. Black
Keyword(s):  
Oxygen Consumption ◽  
Cold Exposure ◽  
Previous Experiment ◽  
Female Rats ◽  
Control Group ◽  
Maximal Rate ◽  
Acute Cold Exposure ◽  
Exposure To Cold ◽  
Rate Of Oxygen Consumption ◽  
Rate Of Cooling

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.

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

1965 ◽  
Vol 209 (1) ◽  
pp. 227-230 ◽  
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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