This article shows an interesting study in which PGE2 inhibits neuronal nitric oxide synthase (nNOS) in the macula densa.
It is well known that cyclooxygenase-2 (COX-2) and nNOS are coexpressed in macula densa cells. PGE2 and NO are produced and both lead to increased renin secretion when there is low sodium and chloride sensed by the macula densa cells.
This study shows PGE2 inhibits nNOS mRNA expression. Also, it shows that COX-2 -/- (no PGE2 present) mice have increased nNOS mRNA expression.
This means that while PGE2 and NO can both independently lead to renin production, the availability of NO is regulated by a negative feedback mechanism by PGE2. It would be a mechanism not to overproduce renin.
Credits
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.
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