Figure 4. UCP2 decreases mast cell histamine content.

(A) Total skin histamine of wild-type and Ucp2^−/− mice quantified by ELISA. Data are normalized to the tissue weight. *P < 0.05. Graph represents the mean and individual data of 6–7 mice per genotype. (B) Representative photomicrographs of dorsal skin from wild-type and Ucp2^−/− mice stained with toluidine blue. Metachromatic mast cells are also indicated by arrows. (C) Number of mast cells per mm² in cross-section of skin. Mast cells were counted in 5 randomly chosen fields from 3 sections per mouse. Data represent the mean ± SD of 5 mice per genotype. P > 0.05. (C) Total histamine content of wild-type and Ucp2^−/− BMMCs was measured spectrophotometrically and normalized to cell number. *P < 0.05 vs. wild-type (t-test). Data is the mean ± SD of three experiments. (D) Total histamine content of LAD2 cells 5 days after transduction with a control lentivirus or UCP2 overexpression lentivirus. *P < 0.05 vs. control cells. Data is the mean ± SD (n=3).