Structure of the kidney of Bufo arenarum: intermediate segment, distal tubule and collecting tubule.
The ultrastructure of the intermediate segment (IS), distal tubule and collecting tubule (CT) of the south american toad Bufo arenarum, was studied by light and transmission electron microscopy. The IS is composed of cubical ciliated cells which propel the urine along the renal tubule. The distal tubule is divided into two portions: the early distal tubule (EDT) and the late distal tubule (LDT). The EDT is characterized by only one type of cells with well developed basolateral interdigitations and numerous elongated mitochondria, which are oriented normal to the basal surface. The "macula densa--like" is a specialized zone of the EDT in contact with the vascular pole, where cells are more tightly packed than in the rest of the tubule. The LDT shows two types of cells called dark and light cells according to the appearance of their cytoplasm. Dark cells have microplicae and few but long microvilli at their luminal surface, and abundant mitochondria in their cytoplasm. Light cells show basal and lateral infoldings and few mitochondria. The CT, which is composed of dark and light cells, exhibits an enlarged lumen with an undulated surface and dilated spaces between neighbouring cells. This work is a contribution to the knowledge of the kidney of B. arenarum; frequently used as an experimental model for physiological and biochemical studies.
Farías
Alejandro
A
Laboratorio de Histología Animal, Departamento de Biodiversidad by Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. chango@bg.fcen.uba.ar
Hermida
Gladys Noemí
GN
Fiorito
Luisa Eleonora
LE
D000818:Animals; D002022:Bufo arenarum / Q000033:anatomy & histology*; D005260:Female; D007668:Kidney / Q000033:anatomy & histology / Q000648:ultrastructure*; D007684:Kidney Tubules / Q000648:ultrastructure*; D007685:Kidney Tubules, Collecting / Q000648:ultrastructure*; D007686:Kidney Tubules, Distal / Q000648:ultrastructure*; D008297:Male