Histochemical factors influencing the sulfation of the mucosubstances of the Brunner's glands of the human duodenum.

The mucopolysaccharides of the human Brunner's glands were sulfated by sulfuric acid diluted with acetic anhydride or nitrobenzene (1:50) in 5 min. They were recognized by toluidine blue at a pH of less than 1 by exhibiting a red-violet or violet-red metachromasia. The sulfated radicals were removed by methanol or butanol with HCl, H2SO4, Na or NaOH, aqueous Ba(OH)2 at 60 degrees C, or by acetic anhydride, acetyl chloride, benzoyl chloride, or bromine water at 25 degrees C. The carbohydrates were altered so that sulfation was prevented by prior treatment with aqueous Ba(OH)2, or by acetic anhydride with pyridine at 60 degrees C and by acetyl chloride and by bromine water at 25 degrees C. Periodic acid Schiff staining was prevented by sulfation with a nitrobenzene: H2SO4 mixture but not by an acetic anhydride: H2SO4 combination in 1 h suggesting an additional sulfate radical at hydroxyl sites 1 or 2. Brunner's glands contain a large amount of a neutral mucopolysaccharide and can be used as a model for testing a large number of chemical and blockage reactions. In nearly all instances, Brunner's glands reacted more like pyloric glands than duodenal goblet cells.