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Updated: Jul 17, 2026

Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium
Published on: September 1, 2015
Endothelial cells regulate proximal tubule epithelial cell sodium transport
1Denver Health Medical Center, University of Colorado Health Sciences Center, USA. STUART.LINAS@UCHSC.EDU
Background:
Proximal tubule epithelial cells are in close contact with the renal microvasculature, but the effect of endothelial cells (ECs) on proximal tubule epithelial cell (PTEC) function is not known.
Methods:
To determine if ECs regulate PTECs, we coincubated ECs with PTECs in a system that permitted cross-talk between the two cell types and the vectorial transport of sodium.
Results:
In the presence (but not absence) of ECs, adding bradykinin or acetylcholine increased cGMP and decreased sodium transport, as well as Na,K-ATPase in PTECs. Interleukin (IL)1B preconditioning of ECs also increased cGMP and decreased sodium transport and Na,K-ATPase in PTECs. Bradykinin, acetylcholine, and IL1B EC-dependent effects were reversed with the nitric oxide (NO) synthase inhibitor L-NNA. In the absence of ECs, the addition of NO donors to PTECs increased cGMP and decreased sodium transport and Na,K-ATPase. 8Br-cGMP also decreased PTEC sodium transport and Na,K-ATPase.
Conclusion:
Endothelial cells regulate PTEC function. This effect is mediated by NO synthase-dependent up-regulation of cGMP in PTECs.
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