Atrial natriuretic peptide in the heart and pancreas

We used antisera to pure atrial natriuretic peptide to localise this peptide by immunocytochemistry in rat and human tissue. We showed that both rat and human atrial cardiocytes gave a positive reaction while ventricular cardiocytes were consistently negative. Peripheral islet cells in rat but not in human pancreas also showed positive staining for ANP. We showed by double labelling techniques that the ANP was present in the glucagon containing cells.