Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to elucidate the cytochemical properties of the membranous structure between enamel and ameloblasts of the rat incisor at the maturation stage, chromic phosphotungstic acid (Cr-PTA) and periodic acid-silver methenamine (PA-silver) techniques for electron microscopy were employed in combination with a digestion test with hyaluronidase, neuraminidase, collagenase or trypsin. Also, acid phosphatase activity of ameloblasts at the maturation stage was examined with a modified GOMORI's metal salt method. An intensely Cr-PTA reactive band approximately 0.1 micron thick appeared along the surface layer of enamel at the transitional stage, and at the very beginning of the maturation stage another intensely Cr-PTA reactive band which was seen by uran-lead stain to be a delicate electron-dense membranous structure appeared as well between enamel and ameloblasts. A lot of cytoplasmic small vesicles or tubular structures, both intensely reactive to Cr-PTA, were observed near the apical membranes of the overlying ameloblasts indicating that those organelles must have been responsible for the secretion of the latter band. Acid phosphatase activity was clearly demonstrated at Cr-PTA reactive large vesicles in the cytoplasm of those cells. The PA-silver staining technique manifested a band heavily deposited with silver grains along the surface layer of enamel, i.e., where the former band existed, but showed no particular reaction at the latter, the band-like layer between enamel and ameloblasts. Hyaluronidase or neuraminidase treatment remarkably decreased the Cr-PTA reaction of the latter band. Trypsin or collagenase treatment, on the other hand, not only eliminated the Cr-PTA reaction but digested the band itself. These results suggest that the membranous structure between enamel and ameloblasts of a rat incisor is not so-called enamel cuticle but a basal lamina produced by overlying ameloblasts and that the basal lamina contains collagenous components even though it lies on enamel.
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PMID:Cytochemical studies of ameloblasts and the surface layer of enamel of the rat incisor at the maturation stage. 21 3

7,12-Dimethylbenz[alpha]anthracene-induced rat mammary tumors were dissociated with collagenase and hyaluronidase and placed into primary culture. In most cultures, specific binding of 125I-labeled ovine prolactin was (i) lower than that for the original tumors unless bovine prolactin (1 microgram/ml) had been added to the dissociation medium, and (ii) varied with the type of growth medium used. The level of prolactin binding in cultured cells was relatively constant for the first 7-10 days. Prolactin binding in cultured cell homogenates was maximal at pH 7.0, proportional to cell protein, specific for prolactin, and reached a steady state by 12 h at 22 degrees C. The half-maximum inhibition of 125I-labeled prolactin binding by unlabeled prolactin was 100 ng/ml for cells grown in 5-1000 ng of prolactin/ml. After prolactin was removed from the growth medium, the level of available binding sites progressively increased, reached a maximum at 48 h and then declined. At 48 h, the dissociation constant for prolactin binding (Kd approximately 1 x 10(-10) M) was comparable to that in tumors. In some cultured tumors, a 48-h treatment with 0.5 or 1.0 ng of prolactin/ml caused an apparent increase in the level of prolactin binding. Prolactin increased DNA synthesis and its removal caused a reduction in [3H]estradiol and [3H]-R5020 binding to cultured cell cytosols.
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PMID:Prolactin receptors in primary cultures of carcinogen-induced rat-mammary tumors. 22 41

Rat submandibular gland cells have been obtained through enzymatic dispersion using chromatographically purified collagenase (EC 3.4.24.3) and hyaluronidase (EC 3.2.1.35) and gentle mechanical force. The recovery of viable cells after the isolation procedure was 59% on the basis of total glandular DNA content. Approximately 60% of the total cell population consisted of acinar cells; less than 8% were immature granular duct cells; and the remainder were intercalated duct, striated duct, and myoepithelial cells. Most of the acinar cells were in acinar-intercalated duct complexes. The integrity of the isolated cells was substantiated by their exclusion of trypan blue, intracellular electrolyte composition, incorporation of [14C]glucosamine into trichloroacetic acid + phosphotungstic acid precipitable material at a linear rate for 1.5 hr, secretory responses to parasympathomimetic and sympathomimetic stimulation, and morphologic integrity as determined by light and electron microscopy. The cholinergic receptors were characterized through investigation of the net transmembrane flux of K+ in response to carbamoylcholine. The alpha-adrenergic receptors were characterized by investigating the net transmembrane flux of K+ in response to norepinephrine stimulation and the beta-adrenergic receptors were characterized by determining the rate of secretion of 14C-labeled mucin after isoproterenol stimulation. A high degree of sensitivity to both cholinergic and adrenergic secretagogues was observed.
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PMID:Functional characteristics of dispersed rat submandibular cells. 22 58

The kinetics of AChE solubilization from intact motor endplates of mouse diaphragm, by collagenase, papain and hyaluronidase, was studied in parallel with the ultrastructural localization of AChE in treated neuromuscular junctions. Hyaluronidase did not solubilize more AChE from isolated motor endplate regions than Ringer's solution itself. Residual AChE activity could be demonstrated histochemically in motor endplates even after the plateau of solubilization by collagenase or papain was reached. Less than 35% of junctional AChE is left after collagenase, and less than 20% after papain treatment, as estimated by the percentage of AChE activity left in the isolated endplate region of the diaphragm after protease treatment. Cytochemically, both proteases had a similar effect on postsynaptic AChE. Residual AChE activity was distributed randomly, adhering to the sarcolemma of junctional clefts. Presynaptic AChE localized in the gap between axon terminal and Schwann cell appears to be resistant to collagenase but not to papain treatment. The mode of AChE attachment or the composition of the intercellular material in this gap may differ from that of the primary and secondary clefts.
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PMID:Attachment of acetylcholinesterase to structures of the motor endplate. 22 95

Cells obtained from male quail kidneys by digestion with collagenase and hyaluronidase were plated and maintained in a chemically defined, serum-free medium. Culture dishes (35 mm) were inoculated with 1.5 . 10(6) cells which became confluent in 5 days. The cells maintained an epithelial-like morphology over the entire culture period. During a 2 h incubation the cells metabolized 25--30% of the 10 nM 25-hydroxyvitamin D-3 (25-OH-D-3) provided. Seven metabolites were chromatographically separated on Sephadex LH-20. Three have been identified as 1 alpha, 25-dihydroxyvitamin D-3 (1,25(OH)2D-3), 24,25-dihydroxyvitamin D-3 (24,25(OH)2D-3) and 1 alpha, 24,25-trihhydroxyvitamin D-3 (1,24,25(OH)3D-3). The activities of the 25-OH-D-3:1 alpha- and 24-hydroxylases increased eight times faster than the cell number in 5 days. Preincubation of the cells with 10 nM 25-OH-D-3 or 1,25(OH)2D-3 decreased 1,25(OH)2D-3 synthesis, and increased both 24,25(OH)2D-3 and metabolite IV synthesis. The decrease in 25-OH-D-3:1 alpha-hydroxylase activity required a 2 h preincubation with 25-OH-D-3, while stimulation of 25-OH-D-3:24-hydroxylase activity and metabolite IV production required a 6 h preincubation. Incubations of cells for 1 h with parathyroid hormone resulted in a 30-fold increase in cyclic AMP in the medium. A 6 h preincubation with parathyroid hormone decreased 24,25(OH)2D-3) synthesis 50% relative to control cells. These results demonstrate the amenability of this system for studying the regulation of 25-OH-D-3 metabolism, as well as its use for other in vitro studies on renal cell function in a chemically defined culture system.
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PMID:Serum-free culture of Japanese quail kidney cells. Regulation of vitamin D metabolism. 22 48

A series of hydrolytic enzymes were compared with lysolecithin, glycerol monooleate, and inactivated Sendai virus for their ability to bring about the fusion of several human and mouse lymphoid cell lines. The agents were tried alone and in various combinations, and a variety of incubation conditions were tested to determine those optimal for fusion. Sendai virus was found to produce the best results with the mouse lymphoid cells; lysolecithin plus glycerol monooleate was slightly superior with the human lymphoid cells. A mixture of hyaluronidase plus collagenase produced low (2 to 6%), but significant, fusion of the human lymphoid cells; both the human and mouse lymphoid cell lines were found to contain relatively high amounts of prolyl hydroxylase, the enzyme which forms collagen from protocollagen. The maximum fusion obtained with the human cells was 16%; with a mouse plasmacytoma line, the maximum was 7.5%; and with a mouse leukemic line derived from L5178Y, the maximum was 60%.
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PMID:Optimal conditions for the fusion of lymphoid cell lines. 24 Jul 76

Pigment migration in cultured erythrophores of the squirrel fish Holocentrus ascensionis, after manipulation with K+, epinephrine, 3',5'-dibutyryl cyclic adenosine monophosphate, theophylline, and caffeine, is essentially identical to that observed in this chromatophore in situ. For such observations, the erythrophores are dissociated from the scales with hyaluronidase and collagenase, and allowed to spread on an amorphous collagen substrate, where they resemble the discoid erythrophore in situ. In this state, they are readily fixed by glutaraldehyde and osmium tetroxide, and are then critical-point dried for whole-cell viewing in the high voltage electron microscope. The organization and fine structure of the erythrophore cytoplast was stereoscopically examined after fixation of the pigment granules in four experimental states: pigment dispersed, pigment aggregated, pigment aggregating, and pigment dispersing. In the dispersed cell, granules are contained in an extensive three-dimensional lattice composed of radially oriented microtubules and a network of fine filaments 3-6 nm in diameter (microtrabeculae), whereas in the aggregated cell, the microtrabecular system is absent, and the majority of the microtubules appear displaced into the cortices on the cytoplasmic surface of the plasma membrane. In cells fixed while aggregating, few microtrabeculae are observed, although formless thickenings are observed in the cortices, on granules, and between clumped granules. In dispersing cells, the microtrabecular system is reformed from material stored in the cortices and with the granules in the centrosphere. These observations suggest that the granules are suspended in a dynamic microtrabecular system that withdraws during pigment aggregation and is restructured during pigment dispersion. The microtubules guide linear granule motion not by defining physical channels, but by a recognizable affinity of microtubules, microtrabeculae, and granules for one another.
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PMID:Transformations in the structure of the cytoplasmic ground substance in erythrophores during pigment aggregation and dispersion. I. A study using whole-cell preparations in stereo high voltage electron microscopy. 26 22

Adenylate cyclase activity in particulate fractions from a transplantable rat osteogenic sarcoma was stimulated in a dose-dependent manner by prostaglandins E1 and E2 (PGE1 and PGE2) and parathyroid hormone (PTH). Prostaglandin F2alpha was active at a high concentration (3 x 10(-4) mol/l). Pretreatment of membranes with collagenase plus hyaluronidase reduced the magnitude of the PTH effect but did not affect the size of the PGE1 effect. Guanosine 5'-triphosphate and its synthetic analogue 5'-guanylylimidodiphosphate (Gpp(NH)p) activated adenylate cyclase in particulate preparations from the osteogenic sarcoma. The latter agent produced much larger effects, although the concentrations required for half-maximal enzyme activation were the same for both agonists (approximately 2 x 10(-6) mol/l). The effects of PTH and Gpp(NH)p were supra-additive at some concentrations of hormone. The effects of PGE1 and Gpp(NH)p were supra-additive at all hormone concentrations tested. Pre-incubation of membrane particles for 6 min with PTH produced an enzyme activation which was not reversed by dilution through washing; pre-incubation with PGE1 did not produce this effect. The response of membrane adenylate cyclase to Gpp(NH)p (10(-4) mol/l) was 75% greater in preparations pre-incubated with PTH than in membranes pre-incubated in buffer alone or in buffer containing PGE1. The basal rate of cyclic AMP production in the adenylate cyclase assay system decreased over a 35 min incubation period. This decrease was prevented by addition of PTH or PGE1. Addition of NaF or Gpp(NH)p produced a steady increase in the rate of production of cyclic AMP with time. Membrane preparations did not reduce the biological activity of PTH and did not degrade 125I-labelled PTH. The results demonstrate that the PTH- and PGE-responsive adenylate cyclases of the osteogenic sarcoma have distinctly different properties and that particulate preparations of the tumour do not metabolize PTH.
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PMID:Membranes from a transplantable osteogenic sarcoma responsive to parathyroid hormone and prostaglandins: regulation of adenylate cyclase and of hormone metabolism. 27 36

The concanavalin A (Con A)-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary epithelial cells was examined. Cells freshly dissociated from normal mammary glands, hyperplastic alveolar nodules, or primary mammary adenocarcinomas by collagenase digestion in the presence of bovine serum albumin were strongly agglutinated by low concentrations of Con A. After short-term culture in vitro, however, cells from all three types of tissue were only weakly agglutinated by Con A, as measured by both suspension and hemadsorption assays. By comparison, cells of three established mammary tumor culture lines agglutinated strongly in the presence of the lectin. Treatment of the normal, preneoplastic, and neoplastic mammary cells in primary cultures with either trypsin or collagenase had little or no effect on their agglutinability, whereas hyaluronidase significantly increased their reactivity. Studies with fluorescein-tagged Con A indicated that all three cell types were capable of binding the lectin. The results were consistent with previous evidence suggesting that neoplastic transformation of mouse mammary epithelial cells is not manifested in vitro by several of the alterations in growth patterns, intercellular interactions, and surface properties that usually accompany transformation of fibroblastic cells.
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PMID:Concanavalin A-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary cells. 28 51

To establish whether the enhanced LH-RH responsiveness shown by pituitary gonadotrophs at proestrus in vivo could be maintained in vitro, rat anterior pituitary cells were investigated to determine differences in LH release in response to LH-RH through the estrous cycle and with time in primary culture. Pooled or individual anterior pituitary glands from each day of the cycle were dissociated with collagenase, hyaluronidase and Viokase and cultured for from 1 to 4 days. Four-day cultures of proestrous cells did not show differences in LH-RH responsiveness when compared to estrous, diestrous I and diestrous II cells. In addition, proestrous cells did not show differences in LH-RH responsiveness when compared to diestrous II cells after 1, 2, 3 or 4 days of culture; however, over the same 1--4 days of culture, proestrous cells contained higher amounts of LH and released greater quantities of LH into the growth medium than did diestrous II cells. It was also observed that both proestrous and diestrous II cells exhibited significantly greater LH-RH responsiveness after 3 or 4 days of culture than after 1--2 days of culture. These results suggest that the differential LH-RH responsiveness shown by pituitary gonadotrophs at proestrus in vivo is not maintained when pituitary cells are placed in primary culture.
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PMID:Cyclic and temporal differences in LH-RH-stimulated LH release in cultured rat pituitary cells. 35 Jun 74


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