Gastric G-cells are a type of secretory cell found in the stomach, mainly in the sinus portion of the stomach, the fundus, and the small intestine, especially the duodenum. It is a large, open cell, conical or long-necked bottle-shaped, with a wide base. This cell receives stimulation from the contents of the glandular lumen chiefly by means of the apical villi, and its secretory granules are chiefly inhomogeneous and accumulate at the base of the cell; the G-cells increase the quantity secreted by means of external stimulation or by nerve-blood regulation. So far there is no chemical tissue reaction that can prove G cells, the only method is immunohistochemistry, but some cross-reactivity can affect the results of the test. the G cells themselves can release product hormones from their apical, basal or lateral surfaces and follow the bloodstream into the glands, thus acting as a transmitter in the circulation.