VIP (human, mouse, rat)

VIP, a 28-amino acid peptide belonging to the secretin-glucagon-CRF family, is widely distributed in the central and peripheral nervous systems. Acting both as a neurotransmitter and as a hormone, VIP is involved in a wide variety of biological activities, including vaso- and bronchodilation, smooth muscle relaxation, and stimulation of secretion. An injectable formulation of this peptide in combination with the adrenergic drug phentolamine is expected to provide a new and effective alternative for erectile dysfunction patients.