The ability of an epithelium to survive removal of the basal lamina by enzymes: fine structure and content of sodium and potassium of the midgut epithelium of the larva of Tenebrio molitor after withdrawal of the basal lamina by elastase--a short note.

A method is described to separate the epithelial cells of the posterior part of the mealworm midgut from their thick basal lamina using elastase. After removal of the basal lamina the naked epithelial cells remain connected with each other, still forming a midgut tube. The ultrastructural changes observed are enlargement of the lateral spaces between the cells and simultaneous destruction of junctional structures other than desmosomes and tight junctions. This enlargement is most probably due to shrinkage of the epithelial cells as a consequence of osmotic stress, which the cells normally seem to be protected against by the basal lamina. The content of sodium and potassium in the epithelium is not influenced by the elastase treatment, indicating that the midgut tube stays alive with intact plasma membranes.