Cold-induced developmental changes in fat cell size and number in brown adipose tissue of the rat.
Seven-week-old Long-Evans rats were acclimated to a constant temperature of either 28 degrees C (control group) or 5 degrees C (cold-acclimated group). Cold acclimation induced a 70% increase in the interscapular brown adipose tissue (IBAT) relative mass, a 35% increase in DNA content, and a 44% decrease in triglyceride (TG) content, which resulted in a 51% decrease of the TG/DNA ratio. A procedure is described by which brown fat cells were isolated, with a yield of 21% from the IBAT of the control group and of 38% in the cold-acclimated group. In both groups, the brown fat cells accounted for 35-37% of the total cells in the tissue. Cold acclimation induced decreases in the mean fat cell diameter (about 20%), the mean fat cell TG content (50%), and the fat cell TG/DNA ratio (50%). The total number of IBAT fat cells was significantly increased in cold-acclimated rats. It is concluded that cold acclimation involves a hyperplasia of the IBAT, associated with a decrease of fat cell size without any alteration of the fat cell-to-nonfat cell ratio.
D000064:Acclimatization; D002001:Adipose Tissue, Brown / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D002452:Cell Count; D002469:Cell Separation / Q000379:methods*; D003080:Cold Temperature; D004247:DNA / Q000378:metabolism; D008297:Male; D051381:Rats; D014280:Triglycerides / Q000378:metabolism
D014280:Triglycerides; D004247:DNA