NPR1 Function in Heart Protection 

• NPR1 (GC-A) is the main receptor for ANP/BNP, hormones released during cardiac stretch. 
• NPR1 activation increases cGMP, promoting vasodilation, natriuresis, and suppression of RAAS—mechanisms that reduce cardiac load. 
• NPR1 signaling limits hypertrophy and fibrosis, key pathological features of heart failure. 

NPR1 Humanized Mice (B-hNPR1) .

• Exons 1–7 of the mouse Npr1 gene, which encode the extracellular ligand-binding domain, were replaced with the corresponding human NPR1 exons 1–7.

Strain specific analysis of NPR1 gene expression in wild-type C57BL/6 mice and B-hNPR1 mice by RT-PCR. Mouse Npr1 mRNA was detectable only in ovary of wild-type C57BL/6 mice (+/+). Human NPR1 mRNA was detectable only in homozygous B-hNPR1 mice (H/H), but not in wild-type mice.