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)

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

Treponema pallidum contains hyaluronidase (Hase) associated with its surface. Experiments were performed to determine the functional role of this enzyme in syphilitic infection. The effects of incubating organisms with rabbit anti-bovine Hase or normal or immune sera were compared. Preincubation of treponemes with anti-Hase resulted in inhibition of treponemal degradation of hyaluronic acid, indicating that these antisera did in fact retard enzyme activity. Anti-Hase did not immobilize or neutralize T. pallidum. In addition, rabbits were immunized with bovine Hase and then challenged intradermally with organisms; subsequent lesion development was not affected. Anti-Hase did not block treponemal attachment to cultured testicular fibroblasts but did inhibit attachment to isolated capillaries. Rabbit amnions were used as an in vitro model for dissemination of T. pallidum. Anti-Hase retarded the penetration of organisms through the amnions. This inhibitory effect was dependent on the presence of amniotic hyaluronic acid. When this glycosaminoglycan was selectively removed, the anti-Hase lost its ability to inhibit treponemal penetration. When exogenous hyaluronic acid was added back to treated amnions, the inhibitory effect of anti-Hase was restored. Evans blue experiments were used to characterize treponeme-induced vascular leakage following intradermal inoculation of T. pallidum. Prior treatment of organisms with anti-Hase reduced dermal leakage of the dye, indicating the involvement of the treponemal Hase in causing vessel leakage. Finally, rabbit testicular infections were used as an in vivo model for dissemination; one testis was infected, and after 10 to 13 days, treponemes in the opposite testis were quantitated. The anti-Hase restricted dissemination of organisms. These findings point to the functional role of the treponemal Hase in facilitating disseminated syphilis.
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PMID:The hyaluronidase associated with Treponema pallidum facilitates treponemal dissemination. 355 82

Retinal pigment epithelial cells from normal, Long Evans (LE) and retinal dystrophic (RCS) rats can be grown in vitro (Edwards, 1977). An improved technique is described which permits a more rapid isolation of RPE cells, and routinely gives high cell yields (30,000-40,000/eye), excellent cell viability (95%), and high plating efficiencies (95-100%). Whole eyes are treated with hyaluronidase and collagenase followed by trypsin. These enzymes degrade components of the extracellular matrix, releasing sheets of RPE from adherent attachments to the retina and choroid. Trypsin was then used to dissociate the sheets into single cells. RPE cells are grown to confluence in primary culture. This technique permits RPE cell isolation from both normal and retinal dystrophic (RCS) rats, 8-15 days of age. Normal cells isolated by this technique consistently show excellent phagocytosis in vitro.
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PMID:An improved method for isolation and culture of rat retinal pigment epithelial cells. 405 92

The binding of Evans blue to collagen and elastin in rabbit aortic tissue and in bovine ligamentum nuchae was studied following circulation in vivo of the dye and incubation in vitro in Evans blue containing plasma, respectively. Using collagenase and elastase, the dye was liberated from both tissues corresponding to their different contents of collagen and elastin. Disc electrophoretic analysis of the liberated dye showed, that it migrated as free Evans blue indicating that the binding of the dye to the macromolecules was due to spatial interactions rather than to fixation at specific prosthetic groups. The capability of collagen and elastin to bind Evans blue was demonstrated with the isolated proteins; it was shown elastin had a higher affinity to the dye than collagen. Treatment of the blued tissue with hyaluronidase and Triton X-100 showed that binding to complex carbohydrates and dye accumulation in the aqueous intra- or extracellular space seems to be negligible.
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PMID:The binding of Evans blue to collagen and elastin in elastic tissue. 620 87