Figure 1
NE induces heterogeneous responses in BA. (a–f) NE-induced thermogenic responses in BA show a negative correlation with ΔΨm. (a) Representative MMP image of BA after 0.1 μM NE treatment. Arrow heads point to BA with mitochondrial depolarization, whereas arrows point to BA with mitochondrial hyperpolarization. Scale bar, 20 μm. (b) The corresponding thermal image (ratio of Rh800 intensity to RhB-ME intensity) after 0.1 μM NE treatment. The result shows the low efficacy of NE-induced thermogenic responses in BA. Some BA show thermogenic responses to NE (arrow heads), whereas others have no response to NE stimulation (arrows). (c) Differential interference contrast (DIC) image of BA. (d) The raw data plots of MMP show subpopulations of depolarization and hyperpolarization in 0.1 μM NE-treated BA. Each colored trace represents a MMP change of a single BA (n=150). (e) NE-induced thermal responses in BA. Each colored trace represents a thermogenic response of a single BA (n=150). (f) The scatter plot of thermogenic responses (d) versus MMP changes (e) induced by NE, which shows a negative correlation (r=−0.73, n=150, and P=2.97×10−26 by Pearson’s correlation coefficient test). The box plots of the depolarization subpopulation and the hyperpolarization subpopulation show significantly different amplitudes of thermogenic responses (P=1.88×10−27, two-sided t-test). (g) The raw data plots of MMP still show two-subpopulations in 10 μM NE-treated BA. Each colored trace represents an MMP change of a single BA (n=102). (h) Thermogenic responses in BA are evoked by 0.1 μM NE (black line, n=150) and 10 μM NE (red line, n=88), respectively. The blue line shows that the NE-induced thermogenic response of BA is inhibited by 1 μM SR-59230 A (n=97). All data points in figures represent mean±s.e.m. (i) A representative scatter plot of pH changes versus MMP changes induced by 0.1 μM NE, which shows a strong negative correlation (red line, r=-0.67, n=75, and P=3.94×10−11 by Pearson’s correlation coefficient test).
