I came across this article (and others) where uridine is mentioned to activate P2Y2 receptors, leading to profibrotic heart thickening side effects.
Uridine triphosphate (UTP) induces profibrotic responses in cardiac fibroblasts by activation of P2Y2 receptors.
https://www.ncbi.nlm...pubmed/20471392
Does supplemental CDP-choline / Uridine have negative effects on heart health?