<prompt> Gastric secretions are increased by all of the following exceptSomatostatinHistamineVagal stimulationGastrin  <response>: Somatostatin released by D cellslocated adjacent to G cellsinhibits gastrin secretion by G cells. -Vagal stimulation inhibits release of somatostatin thus indirectly stimulates H secretion by removing inhibitory effect of somatostatin on parietal cells. -Histamine increases H secretion by acting on H2 receptors on parietal cells. -Gastrin is a hormone secreted by G cells into blood circulation. It stimulates secretory activity of parietal cells chief cells. Reference: Medical Physiology, Indu Khurana 