Advertisement

Research Article Free access | 10.1172/JCI109049

Relationship between Para-aminohippurate Secretion and Cellular Morphology in Rabbit Proximal Tubules

Philip B. Woodhall, C. Craig Tisher, Charles A. Simonton, and Roscoe R. Robinson

Division of Nephrology, Department of Medicine, Durham, North Carolina 27710

Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710

Find articles by Woodhall, P. in: JCI | PubMed | Google Scholar

Division of Nephrology, Department of Medicine, Durham, North Carolina 27710

Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710

Find articles by Tisher, C. in: JCI | PubMed | Google Scholar

Division of Nephrology, Department of Medicine, Durham, North Carolina 27710

Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710

Find articles by Simonton, C. in: JCI | PubMed | Google Scholar

Division of Nephrology, Department of Medicine, Durham, North Carolina 27710

Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710

Find articles by Robinson, R. in: JCI | PubMed | Google Scholar

Published May 1, 1978 - More info

Published in Volume 61, Issue 5 on May 1, 1978
J Clin Invest. 1978;61(5):1320–1329. https://doi.org/10.1172/JCI109049.
© 1978 The American Society for Clinical Investigation
Published May 1, 1978 - Version history
View PDF
Abstract

Previous studies in the mammalian proximal tubule have suggested that para-aminohippurate (PAH) secretion is ∼threefold greater in the straight segment, or pars recta, than in the convoluted segment, or pars convoluta. However, the possibility that the site of maximal PAH secretion might be related better to particular tubule segments as identified by cell type had not been explored. In addition, the presence or absence of differences in PAH secretion between morphologically identical regions of superficial (SF) vs. juxtamedullary (JM) proximal tubules has not been examined. These issues were studied using a combination of histologic methods and measurement of [3H]PAH secretion in isolated perfused tubules. Measurements of microdissected SF and JM proximal tubules from young and adult rabbits revealed that SF proximal tubules were slightly but significantly longer than JM tubules ([young rabbits: SF, 8.69±SE 0.14 mm vs. JM, 7.97±SE 0.13 mm; P < 0.01] [adult rabbits: SF, 10.61±SE 0.28 mm; JM, 9.17±SE 0.19 mm; P < 0.001]). Light and electron microscopy revealed three sequential segments (S1, S2, and S3) along the length of SF and JM proximal tubules as defined by cell type. PAH secretion was measured in each of these three segments by the isolated perfused tubule technique. Net PAH secretion in fmol/mm per min in SF proximal tubules was: S1, 281±SE 21; S2, 1,508±SE 104; S3, 318±SE 46. Corresponding values in JM proximal tubules were 353±SE 31, 1,391±SE 72, and 188±SE 23. Net PAH secretion did not differ between comparable segments of SF and JM proximal tubules. It is concluded that differences in PAH secretion along the proximal tubule correlate best with cell type rather than the arbitrary division of the proximal tubule into pars convoluta and pars recta according to its external configuration. Evidence of functional heterogeneity between comparable segments of SF and JM proximal tubules was not observed.

Images.

Browse pages

Click on an image below to see the page. View PDF of the complete article

Version history
  • Version 1 (May 1, 1978): No description
Advertisement
Advertisement