Effect of intracerebroventricularly infused glucagon on feeding behavior

Administration of pancreatic glucagon into 3rd cerebral ventricle of rats suppressed feeding with potency greater than 1000 times that of peripheral administration. A low dose of glucagon (5 ng) suppressed food intake mainly in short-term and slightly in long-term. A medium dose (25 ng) produced delayed feeding suppression. A high dose (100 ng) suppressed only short-term food intake. From this evidence, it is concluded that intracerebroventricular administration of physiological concentration of pancreatic glucagon suppresses short-term food intake through the hypothalamus. The possible mechanism of feeding suppression by glucagon is discussed.