Evidence of fibrosis during and after FO closure in rat heart.

<p><b>A</b>. H&E staining of FO region in neonates P4 and P7. Reduced cell density is shown by the arrows. Scale bars = 200. <b>B</b>. FAP mRNA expression during FO closure as determined by qRT-PCR. ***p<0.001, n = 3. <b>C</b>. Evidence of fibrosis in the remainder of FO region in adult rat hearts. a. H&E staining; b. Martius Scarlet Blue (MSB) staining. Scale bars = 500 µm. RA, right atrium; LA, left atrium; SP, septum primum; SS, septum secundum.