[Secretin. New views on the oldest digestive system hormone].

For many years secretin, discovered in 1902, has been known as a hormone taking part in the digestion process. In the 70-ties the effects of secretin in other organs than gastrointestinal tract were observed. This fact and identification of a new hormone of gastrointestinal tract, VIP, that resembles the structure and function of secretin have initiated the new era of research work. The sites binding this hormone were found in different organs and the role of stimulation of secretin receptors coupled with G protein were studied. Recently a new classification of the hormones of gastrointestinal tract has differentiated peptides of the secretin family.