Alkaline fixation-resistant acid phosphatases in human tissues: histochemical evidence for a new type of acid phosphatase in endothelial, endometrial and neuronal sites

Histochem J. 2001 Jul;33(7):387-95. doi: 10.1023/a:1013719810231.

Abstract

The effect of pH during formalin fixation on acid phosphatases in human tissues was studied. Lysosomal-type acid phosphatase was sensitive to alkaline fixation, being completely inactive after fixation at pH 9.0. Prostatic and tartrate-resistant osteoclastic/macrophagic types were alkaline fixation-resistant, as was an acid phosphatase localized in endothelium, endometrial stromal cells and intestinal nerves. The latter activity was further separable into fluoride- and tartrate-sensitive beta-glycerophosphatase and fluoride-sensitive, tartrate-resistant alpha-naphthyl phosphatase. The activities appeared to represent either different, tightly associated enzymes or separate activity centres of a single enzyme. Alkaline fixation-resistant alpha-naphthyl phosphatase at endothelial, endometrial and neuronal sites was also well demonstrated in unfixed or neutral formalin-fixed sections as tartrate-resistant activity similar to classical tartrate-resistant acid phosphatase, but these phosphatases appear to be antigenically different. Alkaline fixation-resistant acid phosphatase showed a restricted tissue distribution both in endothelium (mainly in vessels of abdominal organs) and at neuronal sites (only in intestinal nerves). Alkaline fixation-resistant acid phosphatase appears to represent a previously unknown or uncharacterized enzyme activity whose chemical properties could not be classified as any previously known type of acid or other phosphatases.

MeSH terms

  • Acid Phosphatase / analysis
  • Acid Phosphatase / classification
  • Acid Phosphatase / metabolism*
  • Endometrium / chemistry
  • Endometrium / enzymology*
  • Endothelium, Vascular / chemistry
  • Endothelium, Vascular / enzymology*
  • Female
  • Fixatives*
  • Histocytochemistry
  • Humans
  • Lysosomes / chemistry
  • Lysosomes / enzymology
  • Macrophages / chemistry
  • Macrophages / enzymology
  • Male
  • Neurons / chemistry
  • Neurons / enzymology*
  • Placenta / blood supply
  • Pregnancy

Substances

  • Fixatives
  • Acid Phosphatase