Adrenomedullin: a new modulator of vascular tone.

We have discovered a novel hypotensive peptide, designated "adrenomedullin", in human pheochromocytoma extracts. It has potent and long-lasting vasodilatory effects in several vascular systems. In addition to adrenomedullin, another hypotensive peptide, termed PAMP, is also produced from the adrenomedullin precursor. Although initially isolated from human pheochromocytoma and porcine adrenal medullary tissue, adrenomedullin mRNA is highly expressed in several peripheral organs including cardiovascular tissues. Taken together with the presence of adrenomedullin-specific receptors on VSMCs and the significant increase in plasma immunoreactive adrenomedullin levels in patients with hypertension, renal failure and congestive heart failure, adrenomedullin may participate in the pathogenesis of these diseases as a factor regulating blood pressure and circulation.