Abstract: SA-PO296
Three-Dimensional Visualization of the Medullary Tubular-Vascular Relationship in Adult Mouse Kidneys
Session Information
- Fluid and Electrolytes: Basic - II
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid and Electrolytes
- 901 Fluid and Electrolytes: Basic
Authors
- Zhang, Jie, China Medical University, Shenyang, China
- Yang, Jie, China Medical University, Shenyang, China
- Thomsen, Jesper Skovhus, Aarhus University, Aarhus C, Denmark
- Andreasen, Arne A., Aarhus University, Aarhus C, Denmark
- Gu, Ling, China Medical University, Shenyang, China
- Chang, Shi-Jie, China Medical University, Shenyang, China
- Christensen, Erik I., Aarhus University, Aarhus C, Denmark
- Zhai, Xiao-Yue, China Medical University, Shenyang, China
Background
A close spatial relationship between renal tubules and blood vessels in the renal medulla forms the structural basis for urine concentration, but is also the site of acute and chronic kidney injury under certain pathological circumstances. Therefore, a comprehensive understanding of the structure of this area is indispensable for nephrologists.
Methods
The tubule-vessel arrangement through whole mouse medulla was investigated using serial sections with double immunofluorescent staining for CD34 and for either AQP-1 or AQP-2. Subsequently, 525 tubules and 333 vessels were traced with custom-made computer software, and ultrastructurally analyzed using EM.
Results
The main findings were: 1) Descending vasa recta (DVR) and ascending vasa recta (AVR) in the center of the vascular bundle (VB) of ISOM closely accompanied each other starting at the cortex-medulla transition towards the inner medulla and gradually draining into capillaries at papilla; 2) AVR arising from capillary nets of the different levels of the medulla always ran counter-currently in close contact with either descending thin limbs (DTL) or DVR in a VB or with collecting ducts (CD) in inter-bundle regions (IBR). AVR accompanying with type 3 short loop nephron-descending thin limbs (SLN-DTL) mainly drained into arcuate veins, while AVR in close contact with type 1 and 2 SLN-DTL often drained into the lobular veins in cortex; 3) Thick ascending limbs (TAL) from the longest long looped nephrons (LLN) entered into a VB, and ran mainly in proximity to and counter-current to the DVR that originated from same glomeruli; 4) The number of ascending and descending tubules and vessels were almost identical; and 5) In the inner medulla, DVR became thin-walled and fenestrated, closely related to the surrounding tubules or CD.
Conclusion
The present study shows a ubiquitous phenomenon that AVR is spatially arranged with DTL and DVR as well as CD in a counter-current way throughout the whole medulla. This contributes to an efficient reabsorption of water and electrolytes in the filtrate, and makes it sensitive to the damaging factors, such as hypoxia, hyperglycemia, cytotoxity, etc..
Funding
- Government Support - Non-U.S.