VIP [H6]

Vasoactive intestinal peptide (VIP) is a 28 amino acid neuropeptide that has been isolated from various organs like intestine the brain upper respiratory and nasal mucosa, salivary glands, and the male and female genital tracts. It is also identifiable in human eosinophils, polymorphonuclear and mononuclear leucocytes. VIP is also known as a potent stimulant of mucous secretion, vasodilatation, and smooth muscle relaxation in bronchus and many other organs. According to various studies, VIP also has effects on the immune regulation. In the murine immune system, VIP inhibited the proliferative responses of lymphocytes to the T cell mitogens. VIP is also known to have altered preferentially IgA synthesis by lymphocytes from gastrointestinal tissues and spleen. In the human immune system, VIP is known to have inhibited the proliferative response of T lymphocytes to mercuric chloride, and inhibited natural killer (NK) cell function.