Architecture of vasa recta in the renal inner medulla of the desert rodent Dipodomys merriami: potential impact on the urine concentrating mechanism
| Autor: | Tadeh Issaian, Vinoo B. Urity, William H. Dantzler, Thomas L. Pannabecker |
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| Rok vydání: | 2012 |
| Předmět: |
Male
medicine.medical_specialty Fluid and Electrolyte Homeostasis Rodent Vasopressins Physiology Zoology Dipodomys merriami Kidney Concentrating Ability Physiology (medical) Internal medicine biology.animal medicine Animals Dipodomys Kidney Tubules Collecting Rats Wistar Inner medulla Kidney Medulla Aquaporin 1 biology Kangaroo rat Membrane Transport Proteins Vasa recta biology.organism_classification Capillaries Rats medicine.anatomical_structure Endocrinology Urea transport Regional Blood Flow Models Animal Female |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 303:R748-R756 |
| ISSN: | 1522-1490 0363-6119 |
| Popis: | We hypothesize that the inner medulla of the kangaroo rat Dipodomys merriami, a desert rodent that concentrates its urine to over 6,000 mosmol/kg H2O, provides unique examples of architectural features necessary for production of highly concentrated urine. To investigate this architecture, inner medullary vascular segments in the outer inner medulla were assessed with immunofluorescence and digital reconstructions from tissue sections. Descending vasa recta (DVR) expressing the urea transporter UT-B and the water channel aquaporin 1 lie at the periphery of groups of collecting ducts (CDs) that coalesce in their descent through the inner medulla. Ascending vasa recta (AVR) lie inside and outside groups of CDs. DVR peel away from vascular bundles at a uniform rate as they descend the inner medulla, and feed into networks of AVR that are associated with organized clusters of CDs. These AVR form interstitial nodal spaces, with each space composed of a single CD, two AVR, and one or more ascending thin limbs or prebend segments, an architecture that may lead to solute compartmentation and fluid fluxes essential to the urine concentrating mechanism. Although we have identified several apparent differences, the tubulovascular architecture of the kangaroo rat inner medulla is remarkably similar to that of the Munich Wistar rat at the level of our analyses. More detailed studies are required for identifying interspecies functional differences. |
| Databáze: | OpenAIRE |
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