大豆子叶内酸性磷酸酶活性的超微结构定位

开花后３５～５０ ｄ 期间和萌发早期（播种后４～８ ｄ）的大豆（Ｇｌｙｃｉｎｅｍ ａｘ Ｌ．）种子中,酸性磷酸酶主要分布在子叶细胞中的蛋白体内;在内质网内也检测到酸性磷酸酶活性。此外,在萌发早期的部分子叶细胞的质膜外侧及其细胞壁基质中可见密集的酸性磷酸酶活性;而且在近质膜的胞质中常见到一些富含磷酸铅沉淀的胞质小泡,似与质膜融合     

小麦雌配子体发育过程中酸性磷酸酶活性定位

在小麦(Triticum aestivum L.)雌配子体发育过程中,胚囊周围邻近的珠心细胞退化降解,并出现很高的酸性磷酸酶反应,特别是合点部分最强。电镜细胞化学定位也表明退化珠心细胞质中有强烈的酸性磷酸酶活力,它们存在于多层环状的胞质结构中,而远离胚囊的非退化珠心细胞中无上述结构,酸性磷酸酶活性仅出现于液泡中。认为珠心细胞的退化是一种自溶现象。从功能大孢子至七细胞胚囊期,胚囊内部胞质酸性磷酸酶活性很低,合点与珠孔两端的反应强度无明显区別。后期成熟胚囊阶段,反足细胞中出现强烈酸性磷酸酶活性,中央细胞次之,而助细胞及卵细胞中很弱。     

小麦受精过程中酸性磷酸酶的超微细胞化学定位

小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ ）受精前成熟胚囊,除胚囊中央细胞的合点端细胞质中有酸性磷酸酶外,其余部位均未发现酸性磷酸酶。受精时期,以下部位存在酸性磷酸酶活性：卵细胞的细胞核内一部分染色质和细胞质中大部分线粒体;精、卵核融合时两核的核周腔内;退化助细胞合点端细胞质和一些液泡内;进入雌性细胞中的两个精核;胚囊各成员细胞的细胞壁及胚囊周围珠心细胞的细胞壁。二细胞原胚中未见有酸性磷酸酶。早期胚乳游离核染色质上有酸性磷酸酶。小麦受精过程酸性磷酸酶的分布特点可能与卵细胞生理状态的变化和细胞质中线粒体的改组、助细胞的退化、精核的生理状态以及精核与卵核的核膜融合等有关。     

CYTOCHEMICAL LOCALIZATION OF ACID PHOSPHATASE ACTIVITY IN GRANULE FRACTIONS FROM RABBIT POLYMORPHONUCLEAR LEUKOCYTES

When rabbit peritoneal exudates (97% polymorphonuclear [PMN] leukocytes, 2% mononuclear cells) were fractionated by zonal sedimentation or isopycnic centrifugation, four fractions (A, B, C, and D) were obtained, as reported earlier. "A" consisted largely of PMN azurophil granules, "B" of PMN specific granules, and "D" of membranous elements. The source of the more heterogeneous "C" fraction (containing acid hydrolases) was uncertain. To gain further information on the nature of this fraction, cytochemical tests for acid phosphatase (AcPase) were carried out on the starting cells and on the fractions. In intact PMN, lead phosphate reaction product was found in Golgi complexes, perinuclear cisternae, and some azurophil granules (immature forms or disrupted mature forms) of a few cells. The specifics and the intact azurophils were not reactive. Reaction product was also found within Golgi cisternae, secondary lysosomes, and some of the azurophil granules of mononuclear cells. Observations on the A and B fractions confirmed those in situ regarding the localization of reaction product in disrupted PMN azurophils, its absence from specifics, and the latency of the enzyme activity in intact azurophils. In the C fraction, AcPase was found in three structures (a) Golgi cisternae, (b) dense bodies, and (c) small pleomorphic granules Comparison with the starting cells indicates that the Golgi complexes are probably derived from both PMN leukocytes and mononuclear cells, whereas the remaining elements resemble (in size, shape, and density) secondary lysosomes and azurophil granules of mononuclear cells. The results indicate that the bulk of the cytochemically detectable AcPase present in the C fraction is derived from mononuclear cells, rather than from PMN leukocytes     

ACID PHOSPHATASE LOCALIZATION IN RABBIT EOSINOPHILS

Eosinophil (and heterophil) leukocytes of glycogen-induced rabbit peritoneal exudates were fixed for 1½ min in 2% glutaraldehyde and examined for acid phosphatase activity both biochemically and cytochemically. Biochemical assays showed that enzymatic activity had been inhibited by only ~10% under these conditions. The cytochemical reaction in the eosinophil was confined to the granules in which the reaction product appeared in the matrix, not in the crystalline core (or in the core region after the latter's extraction). Granules wherein the matrix was disrupted and the crystalline core degraded or extracted showed the most intense deposition of reaction product, whereas well preserved granules with morphologically intact matrix and crystals were unreactive. Yet, not all disrupted granules gave a positive reaction, indicating that disruption was a necessary but not sufficient condition for reactivity. In many eosinophil leukocytes, most if not all granules were acid phosphatase-positive, provided they had become disrupted to a certain degree. Factors possibly involved in converting the granules from an unreactive to a reactive state are discussed.     

ELECTRON MICROSCOPIC LOCALIZATION OF ACID PHOSPHATASE AND THIAMINE PYROPHOSPHATASE ACTIVITY IN HYPOTHALAMIC NEUROSECRETORY CELLS OF THE RAT

Supraoptic nuclei in the hypothalamus of rats were fixed for the electron microscope by vascular perfusion with solutions of glutaraldehyde followed by post fixation with osmium tetroxide. Cytochemical methods for detection of acid phosphatase and thiamine pyrophosphatase activity have been applied to glutaraldehyde-fixed frozen sections containing the neurosecretory cells. The enzyme activities have been localized to certain Golgi cisternae. Acid phosphatase activity is present in the large (0.4 µ to 1.0 µ) granules or dense bodies which are surrounded by a single limiting membrane; both features characterize these structures as lysosomes. Smaller (0.1 µ) granules also present in the perikarya are generally unreactive towards enzyme activity and resemble in form the neurosecretory granules in the neurohypophysis.     

HISTOCHEMICAL LOCALIZATION OF ENZYMES IN TAPINANTHUS BANGWENSIS: ACID PHOSPHATASE

The distribution of acid phosphatase in the tissues of Tapinanthus bangwensis, a semiparasitic member of the Loranthaceae, and some of its hosts was studied. It has beer possible to work out convenient routine methods of pretreating tissues for histochemical enzyme localization, to modify, where necessary, conventional histochemical techniques for the localization of acid phosphatase, and to evaluate the azo-dye and metal-salt techniques at the optical level. Histochemical localization showed generally widespread activity and similarity in distribution for this enzyme in the parasite and host tissues. Although there is no direct correlation between these localizations and host-parasite relationships, the bearing that the localizations may have on such relationships is discussed in the light of the distributional evidence and the role usually ascribed to this enzyme.     

ULTRACYTOCHEMICAL LOCALIZATION OF PLASMA MEMBRANE-ASSOCIATED PHOSPHATASE ACTIVITY IN DEVELOPING TOBACCO SEEDS

Plasma membrane-associated phosphatase activity was found in integumentary cells of developing tobacco ovules from the megaspore tetrad stage to seed maturity. Enzyme activity is greatest in the innermost layers of the integument from the mature megagametophyte stage on. The egg, zygote, and synergids almost totally lack plasma membrane-associated reaction product, while the antipodals show some activity at their chalazal ends. The endosperm has much plasma membrane-associated phosphatase activity in most of its cells during development, but it is primarily the outermost plasma membranes of the surface cells of the embryo that have associated reaction product. It is concluded that the plasma membrane-associated phosphatase activity is related to active transport of assimilates and that the integument is the most important site of active transport in the young ovule. After fertilization, in addition to the innermost layers of the integument, the endosperm and the outermost cells of the embryo become involved in active transport, which continues to seed maturity.     

LOCALIZATION OF DEHYDROGENASE AND ACID PHOSPHATASE IN THE ABSCISSION ZONE OF BEAN LEAVES

Leaf abscission in Phaseolus vulgaris L. cv. ‘Contender’ is associated with enzymatic changes during and prior to separation. Deblading resulted in a localized increase in dehydrogenase and acid phosphatase in the abscission zone. Increased enzyme activities were observed 24–48 hr after deblading. In debladed plants separation was complete in 6–8 days. At separation, dehydrogenase activity appeared to decrease and localization was specific to the protective layer, while the petiole side had no activity. In contrast, acid phosphatase activity was observed in some layers of cells on the petiole side after separation. Ethylene treatment promoted abscission and separation occurred in 24–48 hr in both debladed and intact plants. No protective layer was formed during ethylene-induced abscission. Enzymatic changes similar to those observed in debladed control plants were observed with ethylene treatment. Ethylene induced an additional abscission layer between the pulvinus and petiole, where an abscission layer normally does not form. In this ethylene-induced abscission layer, similar enzyme activities were detected.     

LOCALIZATION OF ESTERASE AND ACID PHOSPHATASE IN GRANULES AND COLLOID DROPLETS IN RAT THYROID EPITHELIUM

Droplets which stain like colloid occur in the cytoplasm of the thyroid follicular epithelium of the rat following stimulation of the gland by thyroid-stimulating hormone (TSH). The occurrence of droplets was remarkably reduced when the lumen became depleted of colloid. Acid phosphatase and esterase were localized in the thyroid droplets and, in addition, in granules largely around the nucleus. Stimulation by TSH resulted in an increase in the number of droplets containing enzyme. Twenty-four hours after hypophysectomy, enzyme-associated granules were localized at the basal end of the cell and droplets were absent. Intravenous injection of TSH resulted in formation of droplets at the apical end of the cell and migration of enzyme-associated granules toward the apical end of the cell. The droplets were first observed approximately 10 minutes after TSH administration and at this time did not appear to contain enzyme. Within 15 minutes many droplets contained enzyme. The granules were largely localized near the nucleus on its apical side 30 minutes after a dose of 25 milliunits of TSH, but were less well localized following one-tenth this dose. These results indicate that the epithelial cell of the thyroid gland contains preformed hydrolytic enzymes associated with granules (lysosomes). When the gland is stimulated by TSH, droplets are formed from colloid derived from the lumen (phagosomes), and hydrolytic enzymes are transferred from granules to the droplets. The droplets may be intracellular organelles for hydrolysis of colloid and liberation of thyroxine prior to the release of thyroxine into the blood.     

薏苡种子萌发过程中盾片上皮细胞超微结构的变化及酸性磷酸酶的动态

利用酶电镜技术,观察了薏苡种子萌发过程中其盾片上皮细胞超微结构的变化及酸性磷酸酶的动态分布。发现蛋白质体的降解发生在萌发旱期,接着发生了超微结构的明显变化包括:(1)脂肪体的大量降解;(2)各种细胞器如内质网、核糖体、线粒体、质体等的形成、发育及增殖。萌发早期,酸性磷酸酶主要是在种子形成时业已合成的,被贮存在蛋白质体中、细胞核内及内壁上。后期,酸性磷酸酶主要是由内质网新合成的。所有这些存在于细胞内的酸性磷酸酶可能是通过质膜或胞间连丝进入胞间进而释放入胚乳细胞内。     

水稻叶片酸性磷酸酯酶活性及其部分特性

从水稻叶片部分纯化了水解磷酸烯醇式丙酮酸的磷酸酯酶,其Ｋｍ（ＰＥＰ）为０．１ｍｍｏｌ／Ｌ,最适ＰＨ５．３．在偏酸性ＰＨ条件下（ＰＨ４．０～７．２）稳定,对热亦较稳定．酶活性受Ｐｉ强烈抑制．它对其底物要求不专一,能水解多种含磷酯键的化合物．表明它是一种非专一性的酸性磷酸酯酶。各种含磷酯键的代谢物对酶活性起竞争性抑制作用,且表现出叠加性．Ｃｕ（２＋）、Ｚｎ（２＋）和Ｆｅ（２＋）抑制酶活性,Ｍｇ（２＋）、Ｍｎ（２＋）、Ｃａ（２＋）、Ｃｏ（２＋）和ＥＤＴＡ无影响．     

甜菊愈伤组织中的质膜内陷:超微结构和酸性磷酸酶细胞化学定位

对在分化条件下的甜菊 (Stevia rebaudiana)愈伤组织分生区域细胞的质膜内陷进行了超微结构和酸性磷酸酶细胞化学研究。结果表明 ,在不同液泡化状态的细胞中均有质膜内陷存在。在原生质浓密的细胞中 ,质膜呈起伏的波纹状 ,某些部位发生明显内陷 ,大小不等 ,多呈圆球状。在部分液泡化细胞中 ,质膜内陷体积增大 ,内含物增多且结构复杂。在液泡化细胞中 ,质膜内陷嵌入中央液泡 ,但彼此间以一膜间隙隔开。质膜内陷中的内含物以小泡和卷绕的膜结构形式存在。酸性磷酸酶活性定位结果显示 ,质膜及其内陷含高的酶活性。推测质膜内陷在功能上与液泡相似 ,构成了这些细胞水解空间的一部分。     

LOCALIZATION OF ACID PHOSPHATASE IN LIPOFUSCIN GRANULES AND POSSIBLE AUTOPHAGIC VACUOLES IN INTERSTITIAL CELLS OF THE GUINEA PIG TESTIS

The intracellular localization of acid phosphatase in guinea pig testicular interstitial cells was investigated by incubating nonfrozen thick sections of glutaraldehyde-perfused testis in a modified Gomori medium and preparing the tissue for electron microscopy. Lipofuscin pigment granules in these cells contain dense pigment, granular matrix, and often a lipid droplet. Reaction product is seen in the matrix of the pigment granules, and they may therefore be called residual bodies. At least some of the dense pigment appears to be derived from myelin figures and membrane whorls, since suitable intermediates can be seen. Lipid droplets found free in the cytoplasm are another possible source of pigment. In both cases the chemical mechanism is presumed to be autoxidation of unsaturated lipid. Acid phosphatase is present in the inner cisterna of Golgi elements. Enzyme activity also appears in possible autophagic vacuoles bounded by double membranes; the reaction product lies between the membranes. Consideration of the enzyme as a tracer suggests that the autophagic vacuoles are derived from the Golgi complex. Possible stages in the formation of these vacuoles by the inner Golgi cisternae are observed.     

不同代龄及生长状态下2BS细胞的酸性磷酸酶活性及氯酯醒对此的影响

实验以人胚肺二倍体成纤维细胞(2BS)为材料,分别测定了处于不同代龄及不同生长时期的2BS细胞酸性磷酸酶(ACPase)活性。结果发现随着代龄增高,细胞ACPase活性上升。处于同一代龄的细胞,则接触抑制期细胞的ACPase活性显著高于生长期细胞。接触抑制引起的酶活性增高甚至超过代龄增加而引起的ACPase活性上升。30μg/ml的氯酯醒有抑制细胞ACPase活性的作用。