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)

Using the incubated isolated rat retina, the effects of hyaluronidase on the electroretinogram (ERG) and metabolic activities were investigated. Initial experiments established the activity of hyaluronidase needed to liquefy, within 15 to 30 minutes, the vitreous of postmortem human eyes; this concentration was 1,000 units/mL. Rat retinas were superfused with a bicarbonate-buffered, oxygenated medium to which hyaluronidase was added in activities ranging from 100 to 5,000 units/mL. These concentrations of hyaluronidase did not significantly alter the amplitudes of the a waves and b waves of the ERG in comparison to their control amplitudes. Measurements were also made of lactic acid production, oxygen consumption, glutathione content, and adenosine triphosphatase activities in control and hyaluronidase-exposed retinas. In the presence of hyaluronidase, their respective values were similar to the controls for all biochemical factors studied. The present experiments demonstrate that addition of hyaluronidase to an "ocular irrigating" solution results in normal ERGs and normal retinal metabolic activity and suggests the possibility that hyaluronidase may be useful in enzyme-assisted vitrectomy.
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PMID:Hyaluronidase and retinal function. 293 18

Cells isolated from rectal glands of Squalus acanthias, using collagenase and hyaluronidase digestion, retained normal morphological characteristics as judged by light microscopy of 1-micron plastic sections. Their oxygen consumption per unit weight was comparable to that of intact rectal gland studied either in situ, or by isolated perfusion, as well as that of rectal gland slices. Cellular respiration was stimulated by dibutyryl cyclic AMP and theophylline or by vasoactive intestinal peptide which stimulate secretion of chloride by the intact gland. Stimulated oxygen consumption was inhibited by ouabain and bumetanide and was proportional to the concentration of sodium or chloride in the incubation solution. The oxygen consumption of these cells parallels the secretory and metabolic behavior of the intact rectal gland, suggesting that it reflects energy demands for ion transport. The relative ease with which a homogeneous preparation of viable and active cells can be obtained and the apparent preservation of many of their key functional characteristics make this preparation a useful tool for the study of hormone-stimulated ion transport.
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PMID:Isolated rectal gland cells: oxygen consumption and hormonal stimulation. 302 17

We modified and improved enzyme digestion and density gradient separation procedures to obtain fractions of proximal and distal renal tubules with high yield and viability. Kidneys from two anesthetized adult Wistar rats were flushed with Krebs-Henseleit buffer (KHB) and then perfused in situ with recirculated KHB containing collagenase and hyaluronidase at 125 mmHg. Cortices were excised, minced, and incubated in KHB containing enzymes for 35 min at 37 degrees C. Dissociated tubules were removed at 10-min intervals, rinsed, and placed in KHB containing 10% calf serum, vitamins, and amino acids at 4 degrees C. Separation was achieved by suspending the tissue in 45% isosmotic Percoll layered over an undiluted Percoll cushion and centrifuging. Proximal tubules sedimented near the cushion. Distal segments were isolated in the uppermost bands of a second 35% Percoll separation. Viability was greater than 95% as measured by lactate dehydrogenase leakage and quantitated by oxygen consumption and ATP content. Basal oxygen consumption was greater than 33 nmol O2 X min-1 X mg protein-1 in all fractions and was stimulated by succinate and inhibited by amiloride and ouabain. Basal ATP content averaged 9.7 nmol/mg ATP. An average 3.3-fold separation for the proximal fraction and 24.5-fold separation for the distal fraction was assessed by the enrichment of six specific enzyme markers, with several of the markers indicating separations up to 32-fold. Isolated tubules also displayed functional responses to parathyroid hormone and vasopressin. Distal, but not proximal, segments demonstrated significantly increased adenosine 3',5'-cyclic monophosphate formation with vasopressin.
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PMID:Improved separation method for rat proximal and distal renal tubules. 303 59

Goblet cell hyperplasia and metaplasia may be important in the pathogenesis of many respiratory diseases. To study the intracellular mechanisms of mucin synthesis, a purified goblet cell preparation is necessary. We have compared different methods of cell dissociation using cat trachea, a source rich in goblet cells. The most successful method used EDTA to loosen the basement membrane and 1% pronase to dissociate the epithelial cells. Goblet cells recovered from a linear Percoll gradient showed preservation of their ultrastructural detail, trypan blue exclusion, oxygen consumption, and synthesis of a high molecular weight compound resistant to hyaluronidase degradation, consistent with mucous glycoprotein. This method allows the isolation of adequate numbers of purified goblet cells for further study of goblet cell synthetic processes.
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PMID:Goblet cell isolation from cat trachea: a comparison of methods. 313 5

Enzymatic depolymerization of hyaluronic acid (HA) is accompanied by the release of reducing ends irrespective of the linkage cleaved. In this investigation we have examined HA exposed to oxygen-derived free radicals (oxy radicals) in order to determine whether reducing ends are released upon depolymerization. Reducing ends were detected by the assay of Park and Johnson, which is a non-specific but sensitive assay for reducing ends, but only to a minimal degree by the Reissig modification of the Morgan Elson reaction, which will detect N-acetylglucosamine at the reducing end. Exposure of a sample of HA, pre-exposed to streptomyces hyaluronidase, to an oxy radical flux did not result in a decrease in Morgan Elson reactivity thus indicating that post cleavage modification of the reducing end by further reaction with oxy radicals does not account for the lack of Morgan Elson reactivity. In addition reducing ends were also detected by reaction with radiolabelled cyanide to the degree predicted by molecular weight. These findings were interpreted as being consistent with the hypothesis that oxy radical induced depolymerization of HA occurs by preferential cleavage of the glucuronidic linkage thus leaving D-glucuronic acid at the reducing end.
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PMID:The generation of reducing ends by exposure of hyaluronic acid to oxygen derived free radicals. 346 Mar 16

Classical techniques for studying modulations of microvascular permeability have a time resolution of minutes. A newly developed method allows continuous measurement of the electrical resistance of the microvascular membrane in vivo (Olesen & Crone 1983). The technique exploits microelectrodes impaled into the vascular lumen and is based on cable analysis of the vessel. It was applied to venules on the surface of the frog brain to test the effect on microvascular permeability of a wide variety of substances. The following agents increased ionic permeability reversibly within seconds: 5-hydroxytryptamine, bradykinin, ATP, ADP, AMP, phospholipase A2, arachidonic acid, leukotriene C4, oxygen-derived free radicals, ionophore A23187, and unbound Evans blue dye. An irreversible permeability increase was induced by protamine sulphate, neuraminidase, trypsin, melittin, and snake venoms from Crotalus durissus terrificus and Bothrops atrox. The following substances were without effect within an administration period of 5 min: histamine, epinephrine, putrescine, angiotensin II, vasoactive intestinal polypeptide (VIP), substance P, neurotensin, vasopressin, adenosine, PGE2, PGF2 alpha, prostacyclin (PGI2), leukotriene B4, albumin, heparin, plant cytokinins, hyaluronidase, thrombin, wasp venom. Variations in pH between 5.1 and 8.6 did not change permeability. Three conclusions are drawn from the observations: (1) the permeability of cerebral microvessels can be modulated by specific agents, (2) the agents induced changes in the endothelium within a few seconds, and (3) the rapid permeability increase induced by inflammatory mediators was less than two-fold and reversible within minutes.
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PMID:Substances that rapidly augment ionic conductance of endothelium in cerebral venules. 348 16

Sensitized photo-induced changes of vitreous structure were investigated using both in vivo and in vitro model systems. In the former, rabbit eyes were injected with the photosensitizer riboflavin, and in the latter, calf vitreous samples were treated with riboflavin or Methylene Blue prior to irradiation with white light. The active species of oxygen, i.e. singlet oxygen, superoxide anion, hydroxyl radical and hydrogen peroxide, generated by the photodynamic action of the sensitizer, caused significant liquefaction of the calf vitreous in vitro. There was little liquefaction of the rabbit vitreous in vivo, suggesting the presence of a protective mechanism in vivo. hyaluronidase induced significantly greater liquefaction in vitro than either Methylene Blue or riboflavin. This study suggests that loss of gel vitreous structure can result from extensive depolymerization of hyaluronidase by hyaluronidase and less drastic conformation and molecular weight changes in the photosensitized reactions. Although light-induced liquefaction was less marked than enzyme-induced liquefaction, the mechanism of the former is more pertinent to age-related vitreous synchysis.
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PMID:Effects of visible-light irradiation on vitreous structure in the presence of a photosensitizer. 365 77

The isolating agents, one enzymatic (hyaluronidase) and two chemical (sodium citrate and EDTA) have been used to search for the best technique to prepare suspensions of viable cells from chicken cecum and jejunum. Viability of enterocytes was assessed in terms of cell membrane integrity (trypan blue exclusion test), metabolic activity (oxygen uptake, lactate production and ATP content) and monosaccharide cumulative capacity. Results show that: In both cecum and jejunum, membrane integrity is better in cells harvested with citrate than those isolated with hyaluronidase or EDTA; The best metabolic status was found in cecal cells isolated with citrate and in jejunal cells obtained with hyaluronidase; The capacity to support alpha-methyl-D-glucoside gradients is highest in the cells harvested with citrate. The citrate-containing isolation medium is thus considered to yield epithelial cell suspensions with the best functional conditions.
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PMID:Preparation and properties of isolated epithelial intestinal cells from chicken cecum and jejunum. 379 80

A method is described whereby short fragments of rat kidney tubule were obtained when kidney slices were gently dispersed by exposure to collagenase and hyaluronidase. When suspended in buffered saline the fragmented tubules respired actively over a period of several hours, the rate of oxygen consumption being proportional to the amount of cell protein. Oxygen uptake was stimulated by the addition of glucose, lactate, butyrate, alpha-oxoglutarate and other substrates and was decreased by the omission of Ca(2+) from the suspending medium. With alpha-oxoglutarate as the added substrate, dinitrophenol strongly stimulated oxygen uptake. Dinitrophenol had a less-marked stimulatory effect when glucose was the added substrate, and inhibited respiration in the absence of added substrate. Oligomycin inhibited respiration and this inhibition was partially reversed by dinitrophenol. Fragmented tubules synthesized glucose from lactate at a high rate but this capacity for gluconeogenesis was abolished by dinitrophenol and by physically damaging the cells.
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PMID:Preparation and some properties of a suspension of fragmented tubules from rat kidney. 435 29

The effect of N,N'-bis(dichloroacetyl)-1,8-octamethylenediamine on the chemical composition of the rat seminiferous tubules was investigated. Daily oral administration of 62.5 mg/kg for 21 days significantly reduced testis weight (p less than .01), protein nitrogen and enzyme activity of the tubules (p less than .01), increased tubal concentration of ribonucleic acid by 33%, glycogen by 56%, lactic acid by 1406%, and ascorbic acid by 34% and reduced oxygen consumption rate by 32% and bicarbonate by 21%. A total inhibition of hyaluronidase activity occurred. It is concluded that this compound causes metabolic disturbance in the rat seminiferous tubules of an amplitude adequate to stop spermatogenesis.
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PMID:Effect of N,N' -bis(dichloroacetyl)-1,8-octamethylenediamine on the chemical composition of the rat seminiferous tubules. 600 36


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