Displacement of Acid Phosphatase and Alkaline Phosphatase Proteins in the Rat Kidney during a Dehydration Procedure : An Advantage of Ultrathin Frozen Sections for Detecting Precise Localization of an Enzyme Activity
The localizations of acid phosphatase and alkaline phosphatase activities were observed in Epon ultrathin sections of rat kidneys which had been either fixed with 2% glutaraldehyde or 4% paraformaldehyde, or fixed and then dehydrated by ethanol or acetone, and in ultrathin frozen sections of 2% glutaraldehyde fixed specimens. Prior to dehydration, acid phosphatase activity was positive in lysosomes, and alkaline phosphatase activity on the luminal side of brush border membrane. In the kidneys which had been fixed then dehydrated with ethanol, acid phosphatase activity was observed in the cytoplasm near lysosomes and on the plasma membrane, as well as in lysosomes, and alkaline phosphatase activity in the cytoplasm and on the cytosolic side of the brush border. These results seem to in dicate the displacement of enzyme proteins during a dehydration procedure. On the other hand, acid phosphatase activity was clearly localized in lysosomes, and alkaline phosphatase activity on the luminal side of the brush border membrane on the ultrathin frozen sections of rat kidneys which were fixed with 2% glutaraldehyde. The ultrathin frozen sections had not been exposed to organic solvents prior to demonstration of enzyme activities.<BR>The present study shows that an ultrathin frozen section is the most suitable for demonstrating enzyme activities directly on an ultrathin section.
- Acta histochemica et cytochemica
Acta histochemica et cytochemica 28(2), 143-148, 1995-04-01