Premium
Vasopressin‐Escape Does Not Involve Marked Changes in the Ratio of Intercalated‐to‐Principal Cells in the Cortical Collecting Duct
Author(s) -
Chou ChungLin,
Ecelbarger Carolyn M.,
Lee Jae Wook,
Knepper Mark A.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.967.28
Subject(s) - pendrin , intercalated cell , chemistry , paraformaldehyde , distal convoluted tubule , immunocytochemistry , staining , medicine , endocrinology , kidney , biology , microbiology and biotechnology , pathology , nephron , biochemistry , organic chemistry , transporter , gene
The kidney collecting duct plays an important role in vasopressin escape, a phenomenon which helps to lessen vasopressin‐induced hyponatremia. To understand transcriptomic changes during escape, we recently carried out RNA‐Seq on the cortical collecting duct (CCD). A key question to interpret these results, however, hinges on whether the observed changes were attributable to cell remodeling in the CCD. Male Sprague Dawley rats infused with a sustained dose of DDAVP received either a high‐water load (50 mL/day) or a normal water load (25 mL/day). CCDs were collected by manual microdissection from collagenase‐treated kidney cortex at day 4, fixed with 4% paraformaldehyde, followed by immunofluorescent staining with anti‐pendrin ( Slc26a4 ), anti‐proton pump ( Atp6v1b1) antibodies, and DAPI. After acquiring the confocal stack images, automatic cell counting was performed on three dimensional reconstructed tubule images generated by Imaris Image Processing & Analysis Software. For each tubule, we counted the number of pendrin‐positive intercalated cells (IC), the number of pendrin‐negative IC cells, and the number of total cells per mm length of tubule. The total number of IC cells was calculated as the sum of pendrin‐positive and pendrin–negative IC cells. The number of principal cells (PC) was calculated as the total cell number minus total IC cells. With a total of 31 CCD analyzed, i.e., 12 from control rats and 19 from escape rats, we found no significant differences in either the proportion of principal versus intercalated cells, or in proportion of α‐versus β‐intercalated cells between the treatment groups (unpaired students t‐test, n=4). These results suggest that the differences observed in the CCD transcriptome in the early time course of vasopressin escape likely do not involve significant remodeling of the CCD in terms of cell‐type identity.