Histochemical localization of alkaline and acid phosphatase activities in the skin ofMystus (Mystus) vittatus Bl. (Siluriformes)

Summary An attempt has been made to localize alkaline and acid phosphatase activities in the skin ofMystus vittatus by using histochemical techniques. The alkaline phosphatase activity is found in metabolically active cells such as basal columnar cells, mucous cells and polygonal support cells. The acid phosphatase activity is intense in the outermost squamous support cells and in the basal columnar cells. These activities have been correlated with some physiological functions of the epidermis.Acknowledgment. We are thankful to P. Vishwanatham, Government College, Mhow, and Dr R.S. Shrivastava, Holkar Science College, Indore, for providing laboratory facilities and to the Council of Scientific and Industrial Research, New Delhi, for a fellowship for M.S.     

Hexosaminidase and alkaline phosphatase activities in articular chondrocytes and relationship to cell culture conditions.

Hexosaminidase and alkaline phosphatase activities in rabbit articular chondrocytes have been studied under different cell culture conditions. Chondrocytes were cultured in monolayer primary culture, monolayer subcultured to the fifth passage (in vitro aging) and cultured within a collagen gel; enzymatically released cartilage cells were used as control. Under these conditions, the two enzymes behave quite differently in relationship to alteration of the chondrocyte phenotype in culture. Increased lysosomal hexosaminidase activity could be considered to be a marker of the dedifferentiated phenotype in monolayer subculture; membrane alkaline phosphatase activity could be used as a marker of non-proliferating cells.     

Hexosaminidase and alkaline phosphatase activities in articular chondrocytes and relationship to cell culture conditions

Hexosaminidase and alkaline phosphatase activities in rabbit articular chondrocytes have been studied under different cell culture conditions. Chondrocytes were cultured in monolayer primary culture, monolayer subcultured to the fifth passage (in vitro aging) and cultured within a collagen gel; enzymatically released cartilage cells were used as control. Under these conditions, the two enzymes behave quite differently in relationship to alteration of the chondrocyte phenotype in culture. Increased lysosomal hexosaminidase activity could be considered to be a marker of the dedifferentiated phenotype in monolayer subculture; membrane alkaline phosphatase activity could be used as a marker of non-proliferating cells.     

Differential developmental pattern of acid and alkaline phytase and phosphatase activities in rat intestine

Summary Rat intestine was found to show a distinct acid phytase activity (pH optimum 4.7) in addition to that of an alkaline phytase (pH optimum 8.0). The phytase and phosphatase activities were found to differ in their developmental pattern and responded differentially to some inhibitors. Thus the two activities seem to be due to two independent enzymes and are not the activity of a nonspecific phosphatase as has been suspected formerly.     

Differential developmental pattern of acid and alkaline phytase and phosphatase activities in rat intestine.

Rat intestine was found to show a distinct acid phytase activity (pH optimum 4.7) in addition to that of an alkaline phytase (pH optimum 8.0). The phytase and phosphatase activities were found to differ in their developmental pattern and responded differentially to some inhibitors. Thus the two activities seem to be due to two independent enzymes and are not the activity of a nonspecific phosphatase as has been suspected formerly.     

三种方法测定碱性磷酸酶对肝疾病的诊断价值

目的研究血清碱性磷酸酶检测临床肝疾病时的方法学,提高临床诊断价值。方法收集临床不同肝疾病病人的血清,分别用3种方法测定其碱性磷酸酶的活性,并与健康对照组比较作诊断性能分析。结果各肝疾病组血清碱性磷酸酶的活性与对照组相比有极显著差异（P〈0．001）;3种方法分别测定各组之闻的血清碱性磷酸酶活性无显著性差异（P〉0．05）。2．乙基氨基乙醇、2-氨基-2-甲基-1-丙醇、二乙醇胺3种缓冲液测定试剂盒方法测定的灵敏度分别为55．20％、47．96％、51．13％,特异度分别为100％、100％、93．75％。结论血清碱性磷酸酶可以作为各类肝病的临床诊断指标;对肝疾病血清碱性磷酸酶测定用2,乙基氨基乙醇缓冲液的试剂方法测定效果较好。     

Effect of human serum on alkaline phosphatase induction in cultured human tumor cells

The continuous cell lines T 24 and HT-29, derived from human bladder and colon carcinomas, produce term-placental and intestinal alkaline phosphatase, respectively. Growth in hyperosmolar medium or exposure to prednisolone or sodium butyrate induces increased enzyme levels, and combinations of inducers elicit synergistic activity increases. The effect of the inducing agents is strikingly diminished when cells are grown in the presence of high concentrations of human serum, and the synergistic increases are essentially abolished. Major human serum protein fractions do not affect alkaline phosphatase induction.     

Effect of human serum on alkaline phosphatase induction in cultured human tumor cells

Summary The continuous cell lines T 24 and HT-29, derived from human bladder and colon carcinomas, produce term-placental and intestinal alkaline phosphatase, respectively. Growth in hyperosmolar medium or exposure to prednisolone or sodium butyrate induces increased enzyme levels, and combinations of inducers elicit synergistic activity increases. The effect of the inducing agents is strikingly diminished when cells are grown in the presence, of high concentrations of human serum, and the synergistic increases are essentially abolished. Major human serum protein fractions do not affect alkaline phosphatase induction.     

Effect of halogenmethylenebisphosphonates on bone cells in culture and on bone resorption in vivo

Dihalogenmethylenebisphosphonates increase alkaline phosphatase activity and fatty acid oxidation in calvaria cells in culture (Cl2MBP greater than Br2MBP approximately equal to F2MBP). The monohalogen ClMBP and the non-halogenated analogues are less active on phosphatase and inactive on or inhibitory towards fatty acid oxidation. The three dihalogenbisphosphonates and ClMBP inhibit bone resorption in vivo, Cl2MBP most strongly.     

Phosphoprotein phosphatase activity of bovine intestinal alkaline phosphatase

The phosphoprotein phosphatase activity of a commercial preparation of bovine intestinal alkaline phosphatase (EC 3.1.3.1) was examined using phosvitin and dentine phosphoprotein as substrates. Over 90% and 70% of the phosphorus from dentine phosphoprotein and phosvitin were hydrolyzed in 2 h. The optimum pH of the enzyme for the dephosphorylation of phosvitin and dentine phosphoprotein was nearly 6. No protein phosphatase activity was observed when the alkaline phosphatases from bovine liver and pulp were investigated.     

Evidence for the presence of viable endothelial cells in cultures derived from dissociated rat brain

Summary The morphology and histochemistry of dissociated newborn rat brain was studied in tissue culture. Direct microscopy of developing cells, electron microscopy and the alkaline phosphatase activity were used to identify the capillary endothelial cells.Acknowledgments. We thank Dr J. Gripenberg for technical assistance. This research was supported by Finnish Cultural Foundation and carried out during the tenure of a fellowship provided for F. J. from the Finnish-Hungarian Cultural Exchange Program.     

Stimulation of the synthesis and non-competitive inhibition of alkaline phosphatase by theophylline in normal hamster fibroblasts and absence of response in transformed fibroblasts]

Theophylline increases the synthesis of alkaline phosphatase in normal Hamster fibroblasts (activity X6 after 24 hours with theophylline 10-3 M). The enzymatic activity of these cells is inhibited by theophylline in vitro (80% inhibition in the presence of theophylline 10-3 M). The inhibition seems to be non competitive, since the apparent Km of the enzyme is not modified. This stimulator and inhibitor effect of theophylline is absent in Hamster fibroblasts transformed by SV 40 virus.     

Biochemical compartmentation of fish tissues. II. Nonspecific phosphomonoesterases in brain.

The specific activities of acid and alkaline phosphatases in different regions of the brain of 9 nutritionally important fishes were worked out. The region consisting of pituitary, hypothalamus and thalamus showed the highest acid and alkaline phosphatase activities. Least activities of both the enzymes were found in the cerebellum and medulla oblongata. The piscivorous fishes contain the highest acid and alkaline phosphatase activity followed by cat fishes and major carps. The distributional pattern of these 2 enzymes in 4 regions of the brain of 9 fishes is the same.     

Wirkung von Actinomycin auf das Enzymmuster der Rattenniere während der Entwicklung

Summary Actinomycin D causes a marked increase of alkaline phosphatase activity in the zona subcorticalis of the developing rat kidney. The effect is more pronounced in female than in male animals. Acid phosphatase activity increases in males only.     

Comparison of the inhibition of avian and mammalian bone alkaline phosphatases by levamisole and compound R8231

Summary Alkaline phosphatases from mammalian bone are inhibited much more than chick bone alkaline phosphatase by levamisole and compound R8231. Doses of R8231 (10^–4 to 10^–5 M) that almost completely inhibit mammalian alkaline phosphatases do not inhibit the growth of embryonic rat femurs in vitro. R8231 should be an excellent biological probe for the function of alkaline phosphatase in bone metabolism.Acknowledgments. This work has been supported by funds from the Medical Research Council.     

Alkaline phosphatase isozymes in cultured human cancer cells

Alkaline phosphatase, an ubiquitous enzyme is known to exist in several isozymic forms. At least three different isozymes have now been identified in humans. Alkaline phosphatase isozymes are among the substances synthesized ectopically by a variety of human tumors and many continuous cell lines derived from different cancers have retained the capacity to produce these membrane-located glycoproteins. This paper reviews the identification of alkaline phosphatase isozymes in cultured tumor cells and relates these findings with recent developments concerning these cell membrane located glycoproteins.     

Alkaline phosphatase isozymes in cultured human cancer cells

Summary Alkaline phosphatase, an ubiquitous enzyme is known to exist in several isozymic forms. At least three different isozymes have now been identified in humans. Alkaline phosphatase isozymes are among the substances synthesized ectopically by a variety of human tumors and many continuous cell lines derived from different cancers have retained the capacity to produce these membrane-located glycoproteins. This paper reviews the identification of alkaline phosphatase isozymes in cultured tumor cells and relates these finding with recent developments concerning these cell membrane located glycoproteins.     

Effect of epidermal growth factor on growth and maturation of fetal and neonatal rat small intestine in organ culture

Small intestinal explants from pre- and post-natal rats were incubated in an organ culture system in the absence and presence of epidermal growth factor (EGF). The rate of synthesis of small intestinal DNA and protein as well as the activity of lactase and alkaline phosphatase increased rapidly between 17 and 20-day gestational age, whereafter they declined. The maximal incorporation of 3H-thymidine and 14C-alanine into DNA and protein, respectively, was significantly stimulated by EGF (100 ng/ml). EGF had no effect on the activity of either lactase or alkaline phosphatase in the small intestinal explants.     

Über DPNH-Diaphorase und alkalische Phosphatase bei Präimplantationsstadien des Goldhamsters (Mesocricetus auratus Waterh.)

Summary The activity of the DPNH-diaphorase and the alkaline phosphatase were examined in golden-hamster eggs prior to fixation. The reactions for DPNH-diaphorase as well as for alkaline phosphatase were found to be positive already in the undivided egg and in early cleavage stages. The reaction products of both enzyme determinations showed a histophotometrically measurable polar distribution in the cytoplasm, in the one-cell stage as well as in the individual blastomeres of the examined early cleavage stages.     

Alkaline phosphatase in human lymphocyte subpopulations.

The levels of membrane alkaline phosphatase have been measured on different lymphocyte fractions from human peripheral blood separated on bovine serum albumin discontinuous gradients. The peak in enzyme activity was observed in a non-T-, non-B-cell fraction, rich in "null" lymphocytes; the lowest values were found in the fraction with the highest proportion of T-cells.