[Effects of zinc on content of uncoupling protein in cold stress rats].
OBJECTIVE
To study effects and regulatory mechanism of zinc on cold stress in rats.


METHODS
Sixty male SD rats were randomized into 4 groups. Rats of group I and III drank tap water, group II and IV drank high-zinc water[1 mg/(kg.d)], respectively, and 5 days later, rats from group III and IV underwent exposure to cold-15 degrees C for 2 hours. The rectal temperature before and after cold exposure were assayed. Zinc concentration in plasma and tissue were assayed. Radioactivity was measured by liquid glimmer instrument using 3H-GTP binded UCPin mitochondria. The dissociation constant(Kd) and maximal binding(Bmax) was determined from Scathardplot.


RESULTS
The decreased range of rectal temperature during cold exposure of group zinc and control were -2.95 +/- 0.61 and -1.16 +/- 0.39(P < 0.05), respectively. There was a significant increase in the content of zinc in the tissue after cold exposure. With zinc and cold treatment, Bmax increased, Kd remained unchanged.


CONCLUSIONS
Zinc might play an important role in cold stress and cold endurance through increase concentration of UCP in brown adipose tissue mitochondria.
Luo
Wenjing
W
Department of Occupational and Environmental Health, Fourth Military Medical University, Xi'an 710032, China.
Chen
Jingyuan
J
Jiang
Hong
H
Chen
Yaoming
Y
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D001831:Body Temperature; D002352:Carrier Proteins / Q000378:metabolism*; D003080:Cold Temperature; D007473:Ion Channels; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D024101:Mitochondrial Proteins; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological; D000071256:Uncoupling Protein 1; D015032:Zinc / Q000494:pharmacology*
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D000071256:Uncoupling Protein 1; D015032:Zinc