Regulation of cell growth and apoptosis by adrenomedullin.

Adrenomedullin, originally discovered in human pheochromocytoma, has been shown to have potent vasodilatory activity. However, like other vasoactive peptide hormones, its physiological roles have been found to extend far beyond the regulation of vascular tonus, and to include such functions as the regulation of cell proliferation and differentiation. There is a growing body of evidence that adrenomedullin exerts a wide range of effects on cell growth and apoptotic death, and that these effects are dependent on cell type and experimental conditions. Signaling pathways independent of cyclic AMP, such as protein tyrosine kinase(s) and mitogen-activated protein kinases, may play key roles in the regulation of mitogenesis and apoptosis by adrenomedullin.