Atrial natriuretic peptide regulation of vertebrate intestinal ion transport

Atrial natriuretic peptide (ANP), in spite of its name, is synthesized and secreted in vertebrates by both the atria and the ventricles and also a number of extracardiac tissues. Likewise, the list of putative targets of ANP is large and includes, in addition to the kidney and vascular smooth muscle, the ion- and water-transporting intestine. Immunohistochemical staining of the intestine of the euryhaline marine goby Gillichthys mirabilis demonstrates the presence of ANP-ergic neurons in the submucosa suggesting paracrine delivery to intestinal epithelial and smooth muscle cells. ANP inhibits ion absorption across the goby intestine, supportingan osmoregulatory role for ANP.