RT Journal Article
SR Electronic
T1 <sup>123</sup>I- or <sup>125</sup>I-Metaiodobenzylguanidine Visualization of Brown Adipose Tissue
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1234
OP 1240
VO 43
IS 9
A1 Okuyama, Chio
A1 Sakane, Naoki
A1 Yoshida, Toshihide
A1 Shima, Keiji
A1 Kurosawa, Hiroyuki
A1 Kumamoto, Kenzo
A1 Ushijima, Yo
A1 Nishimura, Tsunehiko
YR 2002
UL http://jnm.snmjournals.org/content/43/9/1234.abstract
AB 123I-Metaiodobenzylguanidine (MIBG) accumulations that do not correspond to any tumor are observed occasionally on the medial aspect of the upper back or shoulder of children. The true nature of such accumulations is unknown, and we hypothesized that they represent interscapular brown adipose tissue (IBAT) visualized by scintigraphy. Methods: Wistar rats (7 wk old) received MIBG labeled with 123I or 125I. Autoradiography was performed, and concentrations of the tracer in the interscapular subcutaneous tissue were identified histopathologically. The effects of 6-hydroxydopamine, reserpine, and β 3-adrenergic receptor agonist (CL316,243) on the accumulation were investigated to elucidate the mechanism of uptake into BAT. Results: Autoradiography showed well-defined distinct accumulation in the subcutaneous tissue on the upper back, and hematoxylin-eosin and anti-uncoupling protein 1 antibody staining confirmed that it was BAT. The percentage injected dose per gram in BAT was as high as that in the heart and was quite different from the concentration in white adipose tissue. Preadministration of 6-hydroxydopamine or reserpine resulted in lower MIBG concentrations in BAT. Activation of the β3-adrenergic receptor accelerated the washout of MIBG in BAT and caused an increase in concentration in white adipose tissue. Conclusion: MIBG accumulates in the adrenergic nervous system in BAT, and IBAT is distinguished from the surrounding white adipose tissue. To our knowledge, BAT has not been visualized previously. We showed that MIBG scintigraphy might be suitable for the investigation of BAT and treatment of human obesity.