Cold-induced Mitochondrial Uncoupling Elicits an Immediate ¹⁸F-FBnTP Washout from BAT.

<p>(A) Coronal PET/CT images of BAT acquired at room temperature. (B) ¹⁸F-FBnTP PET images of BAT before and during cold stimulation. Images are segmented using max_50% cutoff value. Each image represents summed activity over 3 min. Beginning of acquisition time of each frame is indicated in upper right corner. Cold stimulation started at the 30 min point of the scan. (C) ¹⁸F-FBnTP time activity curve generated from same animal depicted in (B). (D) ¹⁸F-FBnTP mean uptake measured on 10-min image frame, acquired just before (baseline) and 20 and 50 min after the start of cold stimulation (mean±SD, n = 6). Note the immediate sharp decrease of ¹⁸F-FBnTP uptake upon application of cold stimulation (B and C), and small, but insignificant washout at later time points (D), as well as lack of effect on uptake in heart (D).