APPLICATION OF THE STEREOSPECIFIC INHIBITOR L-PHENYLALANINE TO THE ENZYMORPHOLOGY OF INTESTINAL ALKALINE PHOSPHATASE

作者：Keiichi Watanabe, William H. Fishman · 发表于：Journal of Histochemistry & Cytochemistry · 年份：1964 · DOI：10.1177/12.4.252 · 被引用次数：89 · 研究领域：Alkaline Phosphatase Research Studies、Folate and B Vitamins Research、Porphyrin Metabolism and Disorders

The intestine-specific inhibitor of alkaline phosphatase, l-phenylalanine, has been employed in the study of alkaline phosphatase in rat intestine. Five substrates were used, β-glycerophosphate, o-carboxyphenylphosphate, α-naphthyl acid phosphate, naphthol AS-BI phosphate and naphthol AS-TR phosphate. The hydrolytic rate and specific l-phenylalanine inhibition was most marked in the case of the first three substrates. When formol-Ca fixed, gum-sucrose treated sections of rat intestine were incubated in these substrates in the presence separately of 0.05 Md- and l-phenylalanine and Gomori's calcium-cobalt method was employed, a striking inhibition by the l-isomer was regularly found. Azo dye methods were applied under different conditions of time, temperature and cation concentration in some instances. The contrast was marked but not dramatic in the case of α-naphthyl acid phosphate, and it was evident but not marked in the case of naphthol AS phosphate substrates. These findings have been discussed. The alkaline phosphatase of intestinal epithelial cells (human) grown in tissue culture exhibited great sensitivity to l-phenylalanine. Rat kidney and leukocyte alkaline phosphatase were relatively insensitive under the same conditions. Morphologically, the l-phenylalanine-sensitive alkaline phosphatase in rat intestine is largely confined to the striated border of the epithelial cells. In animals maintained on a high fat diet, azo dye methods demonstrated the presence of fine gra...