Renal vasculature and uriniferous tubules in the common iguana

The pattern of vascular supply and the histology of uriniferous tubules of the kidney in the common iguana were studied by light microscopy of semithin sections and by scanning electron microscopy of microcorrosion casts. The corrosion casts showed a strongly developed renal portal system that forms an extensive capillary network throughout the kidney. Glomeruli are numerous and have a capillary pattern consisting of three to six loose coils of capillaries intercalated between afferent and efferent arterioles. Glomeruli are ovoid in shape and relatively small (mean diameter of the casts: 67 ± 19 μm in short axis and 79 ± 18 μm in long axis). Each glomerulus has a single afferent arteriole and efferent arteriole. The length and volume of the glomerular capillaries per unit volume of renal corpuscle are 0.0029 ± 0.0008 μm/μm³ and 0.321 ± 0.077, respectively. A short neck segment consisting of low epithelial cells is interposed between Bowman's capsule and the proximal tubule. A close association between the distal tubule and the glomerular hilus can be interpreted as a juxtaglomerular apparatus. © 1996 Wiley-Liss, Inc.