<P> Gastrin primarily induces acid - secretion indirectly, increasing histamine synthesis in ECL cells, which in turn signal parietal cells via histamine release / H2 stimulation . Gastrin itself has no effect on the maximum histamine - stimulated gastric acid secretion . </P> <P> The effect of histamine, acetylcholine and gastrin is synergistic, that is, effect of two simultaneously is more than additive of effect of the two individually . It helps in non-linear increase of secretion with stimuli physiologically . </P> <P> Parietal cells also produce intrinsic factor . Intrinsic factor is required for the absorption of vitamin B in the diet . A long - term deficiency in vitamin B can lead to megaloblastic anemia, characterized by large fragile erythrocytes . Pernicious anaemia results from autoimmune destruction of gastric parietal cells, precluding the synthesis of intrinsic factor and, by extension, absorption of Vitamin B. Pernicious anemia also leads to megaloblastic anemia . Atrophic gastritis, particularly in the elderly, will cause an inability to absorb B and can lead to deficiencies such as decreased DNA synthesis and nucleotide metabolism in the bone marrow . </P> <Ul> <Li> Peptic ulcers can result from over-acidity in the stomach . Antacids can be used to enhance the natural tolerance of the gastric lining . Antimuscarinic drugs such as pirenzepine or H antihistamines can reduce acid secretion . Proton pump inhibitors are more potent at reducing gastric acid production since that is the final common pathway of all stimulation of acid production . </Li> <Li> In pernicious anemia, autoantibodies directed against parietal cells or intrinsic factor cause a reduction in vitamin B absorption . It can be treated with injections of replacement vitamin B (methylcobalamin, hydroxocobalamin or cyanocobalamin). </Li> <Li> Achlorhydria is another autoimmune disease of the parietal cells . The damaged parietal cells are unable to produce the required amount of gastric acid . This leads to an increase in gastric pH, impaired digestion of food and increased risk of gastroenteritis . </Li> </Ul>

What type of cells are primarily responsible for the secretion of intrinsic factor