Satiety signals from the gastrointestinal tract

Experiments in rats with crossed intestines have shown that signals arising in a 30 cm segment of upper small intestine do not affect the short-term control of food intake. The combined stimulus of neural and hormonal signals arising in the crossed intestinal segment and of absorbed food do not inhibit intake during a subsequent meal. The relevant satiety signals must arise in either the stomach and upper duodenum or in the lower small intestine. A transplanted stomach study has shown that a hormone released from the stomach is responsible for the termination of a single meal. Other studies show that neural or hormonal signals coming from the lower small intestine are important in the regulation of total daily food intake and in the long-term regulation of body weight.