[Role of Bruch's membrane in the process of metaplasia of the ocular pigmented epithelium of Xenopus laevis].

The metaplasia of pigmented epithelium into retina with the formation of nuclear and reticular layers took place in the experiments with wrapping a sheet of pigmented epithelium from tadpoles up in the Bruch's membrane of adult frogs X. laevis. The implant with de novo formed retina resembled the inverted eye. In those experiments where the Bruch's membrane of tadpoles came into contact with that of adults only depigmentation of the pigmented epithelium cells was observed. The pigmented epithelium metaplasia suggests that the Bruch's membrane is permeable not only for low molecular weight substances, but also for inducing agents. The adult Bruch's membrane serves in the process of metaplasia in the experiments described as a new and limiting system which ensures more orderly formation of new retina.