DEGENERATIVE PHENOMENA IN INTESTINAL EPITHELIUM OF TADPOLE OF ALYTES OBSTETRICIANS LAUR

An involution of the intestinal epithelium is observed both during the metamorphosis of the tadpole of Alytes, when the first fore-limb appears, and a short while before. During this involution, the hyaloplasm of the epithelial cells clears up, the mitochondria dilate and also the vesicles of the endoplasmic reticulum; the latter are transformed into aggregates of thin tubules. Large autolytic vacuoles and their derivatives (dense bodies, myelin bodies) occur. Lipid droplets are frequent as well as microbodies. The desintegrated material is either eliminated in the intestinal lumen, after the opening of the cell apex, or phagocytozed by macrophages. The relations between these ultrastructural alterations and the cellular involution and the fate of the damaged material are analyzed. The role of the lysosomal enzymes in the histolysis and the influence of endocrine factors on this process are stressed. © 1969 Springer-Verlag.