Evidence for adrenal medulla involvement in cold adaptation of preoptic-lesioned rats
Braz. j. med. biol. res
;
24(11): 1163-7, 1991. ilus, tab
Article
in English
| LILACS
| ID: lil-105498
RESUMO
The cold-adaptation process was examined in preoptic-lesioned (PO, 18 rats) and adrenaldemedullated-preoptic-lesioned rats (ADPO, 16 rats). PO rats and ADPO female Wistar rats wee cold acclimatized to 5-C for 2 h a day for 2 weeks, or maintained at 25C, starting one week after the operation. Control animals (20 rats) were sham-operated and then treated exactly like the lesioned rats. Lesions int he PO region caused a decrease in the ability to maintain normal body temperature in a cold environment (5-C for 2h). Theri colonic temperature fell even by the end of the 2nd h of cold exposure (-1.1-C for PO rats and -1.25-C for ADPO rats, P<0.01). However, after 2 weeks of cold acclimattion the PO rats, but not the ADPO rats were able to thermoregulate in the cold and showed a normal increase in interscapular brown adipose tissue weight (79%, P < 0.01). These data suggest that the PO is not an essential link for cold adaptation when a mild col-adaptation methods is used. Furthermore, the data show that increased adrenal medullary activity is required for the cold adaptation process in PO rats
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Index:
LILACS (Americas)
Main subject:
Preoptic Area
/
Adaptation, Physiological
/
Cold Temperature
/
Adrenal Medulla
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
1991
Type:
Article
/
Congress and conference
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