Figure 5.

Defects in the skin barrier function of TGase 1^−/− mice. (A) TEWL was measured in wild-type (+/+), TGase 1^+/− (+/−), and TGase 1^−/− (−/−) neonatal mice. Error bars represent SEM of ten different measurements. (B) In vitro diffusion of mannitol across neonatal mouse skins; transport of [³H]mannitol across skins excised from control (○) and TGase 1^−/− (•) neonatal mice was assayed. The steady-state flux normalized to the initial donor concentration was 1.09 ± 0.09 × 10⁻¹ cm/h in TGase 1^−/− skin, which was more than 1,000 times higher than in normal skin (0.818 ± 0.233 × 10⁻⁵ cm/h). Each data point is expressed as the mean ± SEM of three observations. (C and D) In vivo diffusion of Lucifer yellow in neonatal mice. The fluorescent micrographs show the distribution of Lucifer yellow in the skin of control (C) and TGase 1^−/− (D) mice. Sections were counterstained with propidium iodide. Arrowheads, basement membrane. (Bar, 30 μm.)