Basal lamina components in experimentally induced skin blisters.

The distribution of basement membrane glycoproteins, fibronectin, laminin, and type IV collagen was studied in experimentally induced skin blisters in which the epidermis is separated from the dermis through the lamina lucida part of basal lamina. Fibronectin was found surrounding the blister cavity and in a primary covering formed on the bottom of the blister. Neither laminin nor type IV collagen were incorporated into this clot-like matrix. The layer of laminin found in normal epidermal-dermal junction was found to be cleaved by the blistering method, whereas all type IV collagen antigenicity was confined to the base of the blister presumably due to its location in the lamina densa part of the basal lamina. No interstitial collagens were found in the separated epidermis in accordance with previous ultrastructural evidence. These studies support the proposed role of laminin in the adhesion of epidermal cells to basement membrane collagen.