TY - JOUR
T1 - Axial heterogeneity of rabbit cortical collecting duct
AU - Emmons, C. L.
AU - Matsuzaki, K.
AU - Stokes, J. B.
AU - Schuster, V. L.
PY - 1991
Y1 - 1991
N2 - The rabbit cortical collecting duct (CCD) consists of three major cell types: principal cells transport K+, β-intercalated cells absorb Cl-, and α-intercalated cells secrete H+. We used functional and histological methods to assess axial distribution of these cell types along rabbit CCD. In perfused CCDs, lumen-to-bath Rb+ rate coefficient (an index of principal cell K+ transport) was not different in tubules from outer cortex (1 mm from renal surface) compared with those from inner cortex (2 mm from renal surface), suggesting that principal cell function is homogeneous along the CCD. In contrast, Cl- rate coefficient (a measure of β-intercalated cell function) was twice as high in CCDs from outer compared with inner cortex, suggesting heterogeneity of β-intercalated cells along the CCD. To further investigate these regional differences, we fixed and embedded kidneys and identified three cell types in CCD cross sections using carbonic anhydrase staining and peanut lectin binding. Comparing tubule cross sections from outer with those from inner cortex, we found no axial difference in the fraction of cells that were either principal cells (64%) or total (lectin binding and nonlectin binding) intercalated cells (36%). However, the lectin-binding intercalated cell subset was significantly increased in outer compared with inner cortex. We conclude that there is not heterogeneity of principal cells along the rabbit CCD; however, β-cell number and function are increased in outer CCD. Collecting duct heterogeneity begins within the cortical segment.
AB - The rabbit cortical collecting duct (CCD) consists of three major cell types: principal cells transport K+, β-intercalated cells absorb Cl-, and α-intercalated cells secrete H+. We used functional and histological methods to assess axial distribution of these cell types along rabbit CCD. In perfused CCDs, lumen-to-bath Rb+ rate coefficient (an index of principal cell K+ transport) was not different in tubules from outer cortex (1 mm from renal surface) compared with those from inner cortex (2 mm from renal surface), suggesting that principal cell function is homogeneous along the CCD. In contrast, Cl- rate coefficient (a measure of β-intercalated cell function) was twice as high in CCDs from outer compared with inner cortex, suggesting heterogeneity of β-intercalated cells along the CCD. To further investigate these regional differences, we fixed and embedded kidneys and identified three cell types in CCD cross sections using carbonic anhydrase staining and peanut lectin binding. Comparing tubule cross sections from outer with those from inner cortex, we found no axial difference in the fraction of cells that were either principal cells (64%) or total (lectin binding and nonlectin binding) intercalated cells (36%). However, the lectin-binding intercalated cell subset was significantly increased in outer compared with inner cortex. We conclude that there is not heterogeneity of principal cells along the rabbit CCD; however, β-cell number and function are increased in outer CCD. Collecting duct heterogeneity begins within the cortical segment.
KW - Acid-base
KW - Chloride ion transport
KW - Intercalated cells
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U2 - 10.1152/ajprenal.1991.260.4.f498
DO - 10.1152/ajprenal.1991.260.4.f498
M3 - Article
C2 - 1849361
AN - SCOPUS:0025730253
VL - 260
SP - F498-F505
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 0002-9513
IS - 4 29/4
ER -