Figure 4.

Cultured skin fibroblasts prepared from the proband have increased baseline cGMP levels and greater cGMP responses to CNP. (A) Western blot analysis of membrane NPR-B expression levels in fibroblasts cultured from a control donor and the proband. NPR-B expression was normalized to Na⁺/K⁺-ATPase expression. (B) Baseline intracellular cGMP levels of fibroblasts from the donor and the proband. (C) Effects of CNP on intracellular cGMP levels. Means ± SEM (n = 3); **P < 0.01. cGMP, cyclic guanosine monophosphate; CNP, C-type natriuretic peptide; NPR, natriuretic peptide receptor.