CYTOPHOTOMETRIC QUANTITATION OF GLUCOSE 6-PHOSPHATASE ACTIVITY IN RAT LIVER

Abstract

The Wachstein-Meisel lead sulfide precipitation method was used for the histochemical demonstration of glucose 6-phosphatase activity in fresh-frozen normal rat liver sections. Transmittances, microspectrophotometrically determined over cytoplasmic areas of stained sections, were used to calculate the optical density of the stain. In spite of the fact that no absorption maximum was found, the spectrum of glucose 6-phosphatase stain showed proportional increases with increased incubation time. The extinction at a fixed wavelength was shown to be a linear function of incubation time. Studies in which normal tissues were incubated in buffer-substrate and then removed and reincubated for an additional period of time in buffer-substrate containing a specific inhibitor of glucose 6-phosphatase indicate that the increase in optical density of the stain was a result of glucose 6-phosphatase activity.