C-type natriuretic peptide is a peptide hormone involved in vascular regulation, skeletal growth signaling, endothelial communication, and local control of smooth muscle relaxation. Unlike atrial and brain natriuretic peptides, CNP functions mainly through paracrine and autocrine signaling pathways rather than large-scale endocrine fluid regulation.
The hormone contributes to cartilage growth, bone development, vascular relaxation, endothelial protection, and regulation of extracellular matrix remodeling. CNP also influences microvascular circulation, smooth muscle signaling, and communication between connective tissue structures and vascular systems. Through these actions, the hormone supports coordinated skeletal and vascular adaptation.
CNP is produced primarily by endothelial cells, chondrocytes, nervous system tissues, and connective tissue structures. Additional production occurs within the heart, kidneys, reproductive tissues, and additional endocrine-responsive organs.
The hormone is synthesized as a peptide precursor that undergoes enzymatic cleavage to generate active CNP molecules. Local tissue production is especially important because much of its activity occurs near the site of synthesis within vascular and skeletal environments.
CNP production is regulated by mechanical stress, inflammatory cytokines, endothelial signaling, growth-related pathways, and connective tissue remodeling processes. Shear stress and vascular stimulation can increase endothelial secretion.
The hormone acts through natriuretic peptide receptor-B signaling systems linked to cyclic GMP production and smooth muscle relaxation pathways. In cartilage tissue, receptor activation influences growth plate organization and skeletal developmental signaling. Interactions with nitric oxide pathways and extracellular matrix regulatory systems contribute to tissue adaptation. Through these integrated vascular and connective tissue signaling systems, CNP coordinates endothelial communication, skeletal growth regulation, smooth muscle relaxation, and tissue remodeling.
Endothelial peptide acting via NPR-B to raise cGMP and relax vessels; roles in bone growth.
