This has led to much confusion, because of cross reactivity. A primary regulator of Acid Secretion is the hormone gastrin. In turn, secretion of gastrin into the circulation is also closely regulated. Paracrine and direct sensory inputs to the G-cell modulate secretion by transmitting local signals. Neural input allows G-cell secretion to be regulated through central signals responding to anticipatory input prior to actual digestion of the meal.
Somatostatin secretion is regulated by both neural input and the acidity of the canal.
As will be discussed in the next lecture, neural input from the network of nerves located in the wall of the alimentary canal integrate signals from local inputs and central efferents to regulated gastrin secretion. The paracrine and direct sensory inputs to the G cell modulate secretion by transmitting local signals. However, neural input allows G cell secretion to be regulated through central signals responding to anticipatory input prior to actual digestion of the meal. The mucosal endocrine cells structurally resemble those mucosal cells involved in digestion and absorption in having brush borders. The surface of many of these cells contain 'receptors' for digestive products or other lumenal factors which may promote release of gut hormones.