Identification of laminin domains involved in branching morphogenesis: Effects of anti-laminin monoclonal antibodies on mouse embryonic lung development

Using a series of monoclonal anti-laminin antibodies, the deposition and functional involvement of different laminin domains in the developing lung were investigated. Immunohistochemistry reactivity was largely localized to the basement membrane but was also present diffusely in the extracellular matrix throughout the mesenchyme. Organ cultures of lung explants from Day 12 embryos were used. Although all antibodies penetrated the tissues in culture, only laminin alpha-1 and a-5 antibodies inhibited branching activity. Laminin alpha-2, -3, and -4 antibodies did not alter lung morphogenesis.