ULTRASTRUCTURE OF THE NEPHRON OF THE YOUNG CAMEL CAMELUS-DROMEDARIUS

The present study was under-taken to compare the ultrastructure of the kidney of young camels (Camelus dromedarius) with that of adult kidneys, described previously (Safer et al., '88). Young kidneys are known to produce a urine that is only about half as concentrated as that of adult kidneys (Maloiy, '72; Abo-Salem, '88). While possessing most of the ultrastructural features of adult kidneys, and of mammalian kidneys in general, young kidneys differ from those of adults in several respects. The basal lamina comprising part of the filtration barrier is approximately one-fourth as thick as that of the adult kidney. Young kidneys also lack thickened, heterogeneous basal laminae associated with the parietal layer of Bowman's capsule, proximal convoluted tubules, and the thin segments of the loops of Henle in adult kidneys. In addition, the proximal convoluted tubules of young kidneys contain mixtures of lightly stained and darkly stained cells, while those of adult kidneys possess only lightly stained cells. These differences between young and adult kidneys might in part be related to a greater degree of water deprivation experienced by adult animals.