This article evidences how low sodium chloride concentrations cause macula densa (MD) cells to phosphorylate (activate) MAP kinases. This activation is key for the increased expression of COX-2.

The MAP kinases that are phosphorylated (activated) are p38 and ERK1/2. The initial signaling cascade resulting in NaCl dependent activation of the MAP kinases is not clear yet.

COX-2 is the enzyme which will produce PGE2. PGE2 will in turn exert its action on the granular cells to produce renin

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Renal Corpuscle Image. 2019. Downloaded under a Creative Commons Attribution-Share Alike 4.0 International License from Wikimedia Commons. Author: Shypoetess. No changes were made.

Posts in this series

1. Overview

2. Overview (cont)

3. The Macula Densa Cells May Sense Tubular Salt Content Using a NHE2 Exchanger

4. The Macula Densa Cells Also Can Sense Sodium and Chloride Concentrations Using the NKCC2 Transporter

5. PGE2 Inhibits nNOS in the Macula Densa Cells