[Stimulation of blood flow in fundic mucosa by H+ back diffusion--a protective mechanism? (author's transl)]

H+ back diffusion stimulates blood flow in rabbit fundic mucosa. This increase is linearly related to intraluminal [H+]. The capacity of autoregulation is limited and high rates of H+ back diffusion lead to a fall in intramural pH and development of ulcers. Vasopressin blocks the rise in blood flow and ulcers develop even at low rates of H+ back diffusion.