Villous pseudomelanosisの2例

Abstract

A histochemical study was made of the small intestine with villous pseudomelanosis.Melanosis pigment was also examined on the purpose of comparing with villous pseudomelanosis pigment (Zottenpseudomelanosenpigment).The stroma of the latter means the pigment after sodium dithionite extraction of iron, while that of the former the one after bleaching with 3% hydrogen peroxide.Both of the two pigments may be considered to contain carboxylic groups of waterinsoluble protein, because they have their stroma stained positively by the nile blue sulphate (pH 2.7) staining. The aldehyde-fuchsin (AF)-positive stroma of villous pseudomelanosis pigment is apparently different from the AF-negative stroma of hemosiderin seen in hemorrhagic foci in that the former is considered rich in disulfide groups, because it's coloration with the peracetic acid-AF staining withstands blea ching with 6-hour methylation at 60°C, while melanosis pigment is regarded as containing sulfonic groups, because it's coloration with the AF staining withstands bleaching with 6-hour methylation at 60°C. From the histochemical point of view, therefore, villous pseudomelanosispigment may be said to be an unique pigment whose occurrence is thought to be in association with the iron absorbing and excretory function of the intestinal mucosa.