Assessment of brown adipose tissue activity in rats by 99mTc-sestamibi uptake.
Title | Assessment of brown adipose tissue activity in rats by 99mTc-sestamibi uptake. |
Publication Type | Journal Article |
Year of Publication | 2006 |
Authors | Kyparos, D., Arsos G., Georga S., Petridou A., Kyparos A., Papageorgiou E., Mougios V., Matziari C., & Karakatsanis C. |
Journal | Physiol Res |
Volume | 55 |
Issue | 6 |
Pagination | 653-9 |
Date Published | 2006 |
ISSN | 0862-8408 |
Keywords | Adipose Tissue, Brown, Adipose Tissue, White, Age Factors, Aging, Animals, Body Weight, Electron Transport Complex IV, Male, Mitochondria, Radionuclide Imaging, Radiopharmaceuticals, Rats, Rats, Wistar, Technetium Tc 99m Sestamibi, Thermogenesis |
Abstract | Brown adipose tissue (BAT) physiology and imaging have recently attracted considerable attention. BAT is characterized both by enhanced perfusion and increased mitochondrial activity. (99m)Tc-sestamibi is a lipophilic cationic tracer that concentrates in mitochondria. Data on the accumulation of (99m)Tc-sestamibi in BAT are currently lacking. This study investigates the in vivo (99m)Tc-sestamibi uptake in rat BAT. (99m)Tc-sestamibi was administered in male Wistar rats of various age and body size. (99m)Tc-sestamibi uptake was measured in vitro in BAT and white fat (WF) together with cytochrome c oxidase activity. Both (99m)Tc-sestamibi uptake and cytochrome c oxidase activity were higher in BAT than in WF (P<0.05). (99m)Tc-Sestamibi uptake in both BAT and WF was negatively related to body weight (r = -0.96 and -0.89, respectively) as was the BAT/WF uptake ratio (r = -0.85). These data show a higher (99m)Tc-sestamibi uptake in BAT compared to WF, in agreement with the high mitochondrial content and respiratory activity of the former. The strong negative correlation between (99m)Tc-sestamibi uptake in BAT and body weight (negative allometry), is in accordance to increased needs of thermogenesis in smaller animals. Implications of increased (99m)Tc-sestamibi uptake in BAT in radionuclide imaging are also discussed. |
Alternate Journal | Physiol Res |
PubMed ID | 16497107 |