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)

Release of peroxidase from secretory cells of rat lacrimal gland upon cholinergic stimulation was studied in vitro with single lobules and isolated cells (lacrimocytes). Isolated lobules, kept in Eagle's medium, remain structurally intact and reaction product of peroxidase is confined to cisternae of rough endoplasmic reticulum, elements of the Golgi apparatus, and all secretory granules. Morphologically, exocytosis occurs by membrane fusion and discharge of granule content. The highest rate of peroxidase released from lobules is observed at 10(-4) M carbamylcholine. The specific activity of peroxidase released into the medium is fourfold higher as compared to the lobules. Release of peroxidase is suppressed by atropine when added before or after the addition of carbamylcholine. At 4 degrees C, no peroxidase release occurs upon cholinergic stimulation. The exocytotic release of peroxidase is dependent on energy supply, as indicated by substantial inhibition (at 37 degrees C) under anoxic conditions or in the presence of dinitrophenol, KCN, or carboxyatractyloside. Furthermore, the process is sensitive to colchicine and vinblastine. Isolated lacrimocytes, consiting of 95% secretory acinar cells, are prepared by digestion with collagenase, hyaluronidase, and trypsin. They retain the characteristic polarity of secretory cells in situ, and localization of peroxidase is the same as in lobules. Since isolated lacrimocytes respond to cholinergic stimulation in the same way as lobules, the receptors are not damaged by the isolation procedure and appear to be associated directly with the exocrine cell. Oxygen uptake by isolated lacrimocytes is about 14 nmol O2 X min-1 X 10(-6) cells; it is about doubled by uncoupling with dinitrophenol. Oxygen uptake rises by 20-30% above the resting rate upon cholinergic stimulation. This additional uptake is suppressed by atropine or by added cholinesterase, indicating that continuous receptor occupancy may be required for the energy demand by exocytosis. On the basis of the specific activity of peroxidase in the medium, the energy demand resulting from cholinergic stimulation is estimated to be 0.08 mumol ATP (or energy-rich phosphate bonds) per microgram of protein released from the lacrimocytes.
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PMID:Exocytosis in secretory cells of rat lacrimal gland. Peroxidase release from lobules and isolated cells upon cholinergic stimulation. 95 71

The sources of optical retardation changes and light scattering changes occurring during the action potential propagation of lobster giant axons have been investigated. A technique has been developed for resolving the total transmitted-light intensity change into a retardation change component, dI-r, and a forward direction light scattering change, dI-s. Trypsin, pronase, neuraminidase and hyaluronidase all reduce the magnitude of dI-r without diminishing the action potential, probably by cleaving charged saccharides. Dithiothreitol has no effect. This suggests that glycoproteins and hyaluronic acid polymers at the surface of the axon are involved in the optical responses, either by being passively realigned or by contributing to compression and expansion forces as the membrane electric field changes. Large dI-s responses are generated by trypsin and pronase treatment. The modifying effects of these proteases may be due to modification of the membrane or to increases in the refractive index of the medium surrounding the axon, since similar large dI-s, responses are produced by increasing the refractive index with sucrose. Since large reductions in dIr can be produced without concurrent reductions in the action potential, a significant portion of the optical retardation responses cannot be attributable to structural changes that are causally related to membrane ionic permeability changes during the action potential.
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PMID:Modification of optical responses associated with the action potential of lobster giant axons. 112 18

The coating of mouse myocardial cells has been investigated with a variety of cytochemical methods. The coating of the surface membrane gives a positive reaction with ruthenium red, colloidal thorium, phosphotungstic acid (PTA) at low pH, silver methenamine after periodic oxidation (PA-silver technique) and with silver proteinate after periodic oxidation and thiocarbohydrazide treatment (PA-TCH-silver technique). The coating of the T system gives almost similar results. The nexuses do not react with PTA nor with the PA-silver and PA-TCH-silver techniques, but they are strongly stained with ruthenium red which reveals periodic structures in their gaps. The specificities of the colloidal thorium technique and PAT staining have been tested by chemical treatments (methylation, acetylation, saponification), enzymatic digestions (pronase, trypsin, hyaluronidase, neuraminidase) and carbohydrate extractions (with 0.1 N NaOH and 0.05 M H2SO4). These cytochemical data indicate, considering the specificity of the reactions, that the coating of the membrane surface and the T system contains polyanionic groups. A part of them, at least, would belong to a carbohydrate-containing material (glycoproteins), whereas at the level of nexuses the sugar residues would probably be absent.
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PMID:The coating of mouse myocardial cells. A cytochemical electron microscopical study. 119 63

The structure of dermatan [35S]sulphate-chondroitin [35S]sulphate copolymers synthesized and secreted by fibroblasts in culture was studied. 35S-labelled glycosaminoglycans were isolated from the medium, a trypsin digest of the cells and the cell residue after 72h of 35SO42-incorporation. The galactosaminoglycan component (dermatan sulphatechondroitin sulphate copolymers) was isolated and subjected to various degradation procedures including digestion with testicular hyaluronidase, chondroitinase-AC and-ABC and periodate oxidation followed by alkaline elimination. The galactosaminoglycans from the various sources displayed significant structural differences with regard to the distribution of various repeating units, i.e. IdUA-GalNAc-SO4 (L-iduronic acid-N-acetyl-galactosamine sulphate), GlcUA-GalNAc-SO4 (D-glucuronic acid-N-acetylgalactosamine-sulphate) and IdUA(-SO4)-GalNAc (L-iduronosulphate-N-acetylgalactosamine). The galactosaminoglycans of the cell residue contained larger amounts of IdUA-GalNAc-SO4 than did those isolated from the medium or those released by trypsin. In contrast, the glycans from the latter 2 sources contained large proportions of periodate-resistant repeat periods [GlcUA-GalNAc-SO4 and IdUA(-SO4)-GalNAc]. Periods containing L-iduronic acid sulphate were particularly prominent in copolymers found in the medium. Kinetic studies indicated that the 35S-labelled glycosaminoglycan of the cell residue accumulated radioactivity more slowly than did the glycans of other fractions, indicating that the material remaining with the cells was not exclusively a precursor of the secreted polymers. The presence of copolymers rich in glucuronic acid or iduronic acid sulphate residues in the soluble fractions may be the result of selective secretion from the cells. Alternatively, extracellular, polymer-level modifications such as C-5 inversion of L-iduronic acid to D-glucuronic acid, or sulphate rearrangements, would yield similar results.
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PMID:The copolymeric structure of dermatan sulphate produced by cultured human fibroblasts. Different distribution of iduronic acid and glucuronic acid-containing units in soluble and cell-associated glycans. 121 88

In frog cutaneous-pectoris muscles the frequency of slowly rising atypical miniature endplate potentials (MEPPs) was significantly enhanced after collagenase (0.1%) treatment. Treatment with trypsin, hyaluronidase, hyper- and hypoosmotic solutions caused no changes in slowly rising MEPP (frequency in muscle fibers with intact acetylcholinesterase (AChE). Inhibition of AChE caused appearance of giant MEPPs. Acceleration of acetylcholine diffusion from synaptic cleft after treatment with hyaluronidase decreased giant MEPP frequency demonstrating their dependence upon nonhydrolyzed acetylcholine in synaptic cleft. The relation between slowly rising MEPPs and activity of synaptic Schwann cells in discussed.
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PMID:[Atypical endplate miniature potentials in the frog neuromuscular junction after modification of the intercellular matrix and osmotic exposures]. 129 72

The interstitium is the final link in the transportation of nutrients from the bloodstream to the individual cells of an organism. To assess interstitial fluid transport in normal and inflamed tissue, the hydration (H, ml H2O/g dry wt) and hydraulic conductivity (Kp, 10(-8) cm2.s-1.cmH2O-1) of bovine pericardial stroma were determined. The effect of enzymes and neutrophil-derived products of inflammation on the properties of the interstitial model were determined. Samples of the pericardium were exposed separately to trypsin, elastase, hyaluronidase, collagenase, superoxide radicals, and hydrogen peroxide. After exposure, the tissues were washed repeatedly in physiological saline and equilibrated in transport chambers heated to 37 degrees C and pressurized to 50 cmH2O. Fluid flow across the tissues was monitored. A section of tissue was removed and weighed. The tissue section was subsequently dried and reweighed. Tissue thickness, H, and Kp were calculated. H and Kp of the control tissues were 2.82 +/- 0.04 and 1.71 +/- 0.07, respectively. Hydration was significantly increased (22-38%) by exposure to trypsin, elastase, collagenase, and superoxide radicals. Kp increased significantly (30-1055%) in the groups treated with trypsin, hyaluronidase, collagenase, and superoxide radicals. The inflammatory mediators generally increased the hydration and/or the hydraulic conductivity of the model. These results indicate that neutrophil-derived products could be involved in the development of interstitial edema during the inflammatory process.
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PMID:Oxygen radicals, enzymes, and fluid transport through pericardial interstitium. 131 Feb 33

Although it is known that rapid expansion of the vertebrate brain begins near the time that the spinal neurocoel is occluded, it still remains unknown when occlusion occurs in relation to neurulation. Since both morphogenetic events are critical for normal brain growth, it is important to decipher the temporal relationship between the two processes. This study assessed the temporal relationship of the two events with the rationale that if it could be demonstrated that occlusion occurs coincident with the completion of neurulation, then it could be argued that factors shown to direct neurulation could also initiate occlusion. Nearly 600 chick embryos (stages 9- through 12+) were cultured atop egg-agar, the caudal extent of neurulation determined, the cranial five pairs of somites removed and the neurocoels assessed for occlusion. In stage 9- through 10- chicks, neurulation of the spinal cord is incomplete. Stages 10 through 12+ exhibit neurulation and occlusion from the 8th to 19th somites. When lateral tissues were removed in embryos 8 through 10-, the neural folds became dysraphic whereas in embryos stage 10 and older, the folds remained fused dorsomedially and occluded. The only surgical manipulation that was found to prevent occlusion was elimination of the lateral tissues responsible for elevation and closure of the neural folds. Analysis of particular components of the lateral tissues essential for convergence, by treating embryos (n = 75) with chemicals known to degrade tissue-tissue bonds or specific components of the perineural matrix, indicated that more than 75% of the embryos treated with EDTA, EDTA plus Ca2+, trypsin, collagenase, or hyaluronidase exhibited little or no effect on convergence, dorsomedial fusion, and concomitant occlusion.
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PMID:Evaluation of neural fold fusion and coincident initiation of spinal cord occlusion in the chick embryo. 132 5

To determine whether a recognition mechanism is involved in determination of sympathetic innervation patterns of various tissues, tissue-derived substances were applied to a restricted test surface region of dishes and the responses of cultured sympathetic neurites were examined. Sympathetic fibers exhibited a turning or ramifying response, resulting in a dense fiber growth on test regions coated with particulate (adheron) fractions of a conditioned-medium (CM) from expansor secundariorum, heart, peripheral blood vessel or abdominal aorta, whereas on test regions coated with those from lung, skeletal muscle or dorsal aorta the neurite growth was repelled and sparse fiber growth was observed. Particulate fractions of brain- or gizzard-CM had no effect. These patterns in vitro were in parallel with the dense sympathetic innervation in expansor secundariorum, heart, peripheral blood vessel and abdominal aorta, but little or no sympathetic innervation in lung, skeletal muscle and dorsal aorta in vivo. These results suggest that adheron particles may participate in determination of sympathetic innervation patterns. Activity which repels or promotes the sympathetic fiber growth was inactivated by pronase E or trypsin but not by DNase or neuraminidase. Repelling activity was lost after treatment with heparinase or heparitinase but not with chondroitinase ABC or hyaluronidase. Promoting activity was retained after treatment with these glycosidases. These results suggest that the factor(s) possessing a repellent effect is a heparan sulfate proteoglycan and one(s) possessing a promoting effect is a protein.
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PMID:Characterization of substances which promote or repel sympathetic fiber growth in vitro. 133 24

Testes from adult (90-120-day-old) rats, which had been made cryptorchid 28 days previously, were dispersed by successive treatment with trypsin, collagenase and hyaluronidase. The resulting crude cell suspension was fractionated on discontinuous Percoll density gradients to yield five distinct cell bands (1-5), at the interface between successive layers of Percoll. Crude cells and purified fractions were cultured for up to 7 days, and inhibin was subsequently measured in the media by radioimmunoassay and in vitro bioassay. Sertoli cells from density gradient bands 2 (1.03-1.04 g/ml) and 3 (1.04-1.05 g/ml) showed minimal germ cell or peritubular cell contamination, as determined by morphological and histochemical techniques. Cells from these bands secreted significantly higher levels of immunoactive inhibin/microgram DNA/48 h under both basal and either follicle-stimulating hormone (FSH)- (100 ng/ml) or dibutyryl cAMP-stimulated (100 micrograms/ml) conditions than did cells from the other bands. While there was a decline in basal secretion of inhibin with increasing duration of culture, the capacity of the purified Sertoli cells (bands 2 and 3) to respond to both FSH and dibutyryl cAMP increased over the culture period. The addition of dibutyryl cAMP (31.25-500 micrograms/ml) to the purified Sertoli cells also caused a stimulation of bioactive inhibin. Immunoactive inhibin production by purified Sertoli cells was unaffected by the addition of either rat LH (8 ng/ml) or testosterone (10(-6) M). The data describe a method for the isolation of adult Sertoli cells from cryptorchid testes, and demonstrate their responsiveness to both FSH and dibutyryl cAMP in vitro using the measurement of immunoactive inhibin as a marker of Sertoli cell function.
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PMID:Characterisation of adult Sertoli cell cultures from cryptorchid rats: inhibin secretion in response to follicle-stimulating hormone stimulation. 135 83

The structure, distribution and composition of the extracellular matrix present around the human oocyte and in the cumulus was examined following fixation in the presence of ruthenium red. An extracellular matrix comprising granules and filaments is present in the cumulus layer, in the corona radiata, in the outer pores of the zona pellucida and in the perivitelline space surrounding unfertilized oocytes. In replicate samples, the extracellular matrix comprised filaments which were mostly very long, occasionally cross-connected by shorter filaments, and usually decorated with numerous small granules. Enzymatic digestion with affinity-purified trypsin or Streptomyces hyaluronidase removes the granules and filaments, respectively, at all levels of the oocyte-cumulus complex. These results are interpreted to mean that protein and hyaluronic acid are present in all extracellular compartments of the human oocyte-cumulus complex. The significance of this distribution of hyaluronic acid with respect to the role of sperm hyaluronidase in fertilization is discussed.
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PMID:Structure, distribution and composition of the extracellular matrix of human oocytes and cumulus masses. 137 34


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