Thermogenic and lipogenic activities in brown adipose tissue of I-strain mice.
The thermogenic capacity of brown adipose tissue has been investigated in I-strain mice to determine whether this tissue could play a role in the lower efficiency of food utilization reported in this strain of mice. (1) As compared with C57BL mice (a control strain), interscapular-brown-adipose-tissue weight and lipid percentage were decreased by 40% and 13% respectively in I-strain mice. (2) Mitochondrial protein content and cytochrome c oxidase activity were similar in the two strains, but the number of mitochondrial GDP-binding sites and uncoupling-protein content were increased by 2-fold in I-strain mice. (3) Fatty acid synthetase and citrate-cleavage enzyme (units/mg of protein) were 3-fold higher in the brown adipose tissue of I-strain mice. These results indicate that I-strain mice possess a very active brown adipose tissue. This enhanced capacity of energy dissipation in brown adipose tissue could contribute to the decreased capacity of I-strain mice to store adipose tissue.
D001275:ATP Citrate (pro-S)-Lyase / Q000378:metabolism; D002001:Adipose Tissue, Brown / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D064429:Fatty Acid Synthases / Q000378:metabolism; D006358:Hot Temperature; D008055:Lipids / Q000096:biosynthesis*; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008928:Mitochondria / Q000378:metabolism; D011506:Proteins / Q000378:metabolism
D008055:Lipids; D011506:Proteins; D008291:Malate Dehydrogenase; D064429:Fatty Acid Synthases; D001275:ATP Citrate (pro-S)-Lyase