The Structure of Anuran Podocyte—Determined by Ecology?

Abstract

Abstract The podocytes of ten frog species with different habitat preference were investigated by scanning electron microscopy. The visceral epithelium within these species shows considerable variation in the branching mode of the cellular processes, in the number of pedicels and in the form of cell bodies. The presence of various podocyte cell forms within anurans of one family (e.g. within Ranidae and Discoglossidae) indicates that podocytic structure is not manifested phylogenetically. The complexity of processes and pedicel numbers are high in glomeruli of terrestrial and semiterrestrial frogs but low in aquatic and semiaquatic animals. Consequently, podocyte structure is (a) correlated with environmental conditions and (b) plays an important role in osmoregulation. Furthermore, since podocytes are suggested to serve as stabilizers of glomerular vessels, the cells of the visceral epithelium provide the structural basis for regulation of glomerular filtration rate, e.g. for glomerular intermittency.