Immunohistochemical localization of atrial natriuretic peptide in primary aldosteronism

Using the immunoperoxidase method with specific antibody, we examined the presence of atrial natriuretic peptide (ANP) in adrenal tissues of a patient with primary aldosteronism and those derived from a patient with Cushing's syndrome. We found cells immunopositive for ANP in primary aldosteronism but not in Cushing's syndrome. In primary aldosteronism, we noted positively stained cells mainly but not exclusively in the adenomatous tissue. These results demonstrate for the first time the presence of immunoreactive ANP in adrenal tissues of a patient with primary aldosteronism and suggest that adrenal ANP may have potentially important impacts on aldosterone secretion in this disorder.