ULTRASTRUCTURE AND FUNCTION OF VENTRAL EPIDERMIS IN TRITURUS-VITTATUS(JENYNS) LARVAE

Ventral epidermis ultrastructure and function of the newt's Triturus v ittatus (Jenyns) larval stage has been studied. The epidermis consists of an outer layer and an inner layer. The outer layer is composed mos tly of pavement cells, containing a large number of PAS-positive mater ial enclosed in vesicles that are localized in the apical part or thes e cells. Their outer face is covered by short microvilli. The inner la yer is characterized by the presence of numerous, about 19.56 cells/mm , large Leydig cells that contain large vacuoles and RER, and are char acterized by a supporting structure - the Langerhans net. Finally, lar ge, germinative cells rich in tonofilaments can be observed situated o n the basement membrane. The larval epidermis of the newt appears to b e rather active in transport of ions since K+-PNPPase reaction, indica tive of ATPase activity, was localized both on the basolateral membran es bordering the intercellular spaces between the pavement cells, and for the first time localized also intracellurly in the Leydig cells.