Computer-assisted 3D Reconstruction of Mouse Connecting Tubule / 中国医科大学学报

ABSTRACT

Objective To study the spatial arrangement of mouse connecting tubules（CNT）and their transition to collecting duct system.Methods The renal tissues of three C57/BL/6J mice were fixed by perfusion and embedded in Epon 812.Totally 2 000 consecutive sections with the thickness of 2.5 μm were obtained from the renal surface to the papilla.The serial images under microscope were digitalized and aligned.Thirty eight CNT were traced with a series of computer programs.Results The CNT from long loop nephron ascended towards renal capsule and merged with 5 to 6 CNT from short loop nephrons to form the so-called arcade,while the latter or some of the CNT from the superficial cortex directly drained into the collecting duct in the superficial cortex.The lengths of CNT and the arcade ranged from 150 μm to 500 μm and 600 μm to 900 μm respectively.Conclusion The arcade or CNT drains into collecting duct only at superficial cortical level,which suggests that the reabsorption of the glomerular ultra-filtration in collecting ducts keeps unaffected when collecting duct runs through middle to deeper cortex.