THE HISTOCHEMICAL DEPHOSPHORYLATION OF CERTAIN SUGAR PHOSPHATES, α-NAPHTHOHYDROQUINONE DIPHOSPHATE AND TWO CHALCONE DIPHOSPHATES

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Abstract
Judged only by histochemical distribution and intensity of reaction, glucose-1-phosphate, galactose-6-phosphate, fructose-1-phosphate and a naphthohydroquinone diphosphate appear to be hydrolyzed in rat tissues by non-specific phos-phatase at pH 9.0. Sorbose-1-phosphate, on the other hand, appears in some organs to be hydrolyzed either by an enzyme having an identical distribution with non-specific phosphatase or by the latter itself, or in other tissues by an enzyme which shows some differences in distribution from the non-specific phosphatase. 34[image] -Dihydroxy-4-methoxy chalcone diphosphate appears to be hydrolyzed almost exclusively by nuclei although the brush borders of the kidney and intestinal epithelium appear to be able to split it also. The reaction with 2[image] :3-dihydroxy-4:4[image] dimethoxychalcone diphosphate on the other hand, is less localized in the nuclei and in addition the cytoplasm of many cells shows a strong reaction. The difference of distribution of the reaction between these dihydroxychalcone diphosphates and glycerophosphate and between each other suggests that 2 separate enzymes may be involved in hydrolyzing them although one cannot tell to what extent the activity of these suggested enzymes overlap with each other or to what extent their activity overlaps with that of non-specific phosphatase. It is suggested that there is a spectrum of phosphatases with overlapping substrate-specificity.