Cold acclimatization (4-5 C) is accompanied by 2-3 fold increase of
brown adipose tissue (BAT). This rapid growth of interscapular BAT was
studied after histamine depletion. In control rats maintained at room
temperature (28 +/- 2 C) the BAT histamine content was 23.4 +/- 5.9 (mean
+/- SD) ug/g of tissue and cold acclimatization (5+/-1 C) produced a
significant increase of BAT weight, but reduced the histamine content to
8.4 +/- 1.9 ug/g. The total weight of BAT after 20 days of acclimatization
was unaffected by depletion of histamine due to compound 48/80. The low
level of histamine in BAT of cold acclimatized rats could be due to a fast
rate of amine utilization; alternatively an altered synthesis or storage
process may occur during acclimatization.
