Figure 1.

Organ-specific mRNA and protein expression levels of CLDN1, 2, 4 and 5 in the canine duodenum, lung, liver and kidney. mRNA expression levels of (A) CLDN1 were greatest in the lung and kidney, whereas (B) CLDN2 and (C) CLDN4 mRNA was primarily expressed in kidney. (D) CLDN5 mRNA expression levels were low. (E) CLDN1 protein expression levels were high in the kidney, low in the lung and undetectable in duodenum and liver. (F) CLDN2, (G) CLDN4 and (H) CLDN5 protein expression was detected only in the kidney. mRNA and protein expression were normalized to β-actin. Data are presented as the mean ± standard deviation. CLDN, claudin; ACTB, β-actin; D, duodenum; Lu, lung; Li, liver; K, kidney.