A composition and method for enhancing paracellular transport across cell layers in an animal comprising an antisense oligonucleotide hybridizable with a region of the messenger RNA coding for the protein occludin which, when hybridized to the occludin mRNA, interferes with its translation such that occludin function is disrupted and paracellular permeability is increased across an epithelial cell layer or and endothelial cell layer in an animal.