Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blood pressure (BP), plasma prekallikrein (PK), and the extent of activation of factor XII (XII-ACT) were studied after the intravenous injection into rats of dextran (Macrodex), the ionic radiographic contrast substance iodipamide (Biligrafin), or the non-ionic contrast substance iohexol (Omnipaque). After acetone activation plasma kallikrein was assayed as plasminogen activator, BAEe esterase or S-2302 amidase, and factor XIIa was assayed as kaolin-activated prekallikrein activator. Dextran induced a strong and lasting hypotension, preceded by significant lowerings in PK and XII-ACT. Iodipamide induced a rapid and dose dependent BP fall, no change in plasma PK, but a slightly reduced XII-ACT. Iohexol induced no significant alterations, neither in BP, nor in plasma parameters. Pretreatments of the rats with iodipamide abolished the dextran-induced reductions in PK and XII-ACT, and almost blocked the fall in BP. We conclude that the ionic contrast substance iodipamide is capable of blocking dextran shock in the rat by preventing an activation of the contact activating system in plasma.
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PMID:Effects of intravenous radiographic contrast media on the blood pressure and on factors of the contact activation system in the rat. 243 54

The effects of zona pellucida glycoproteins, sulfated polymers and non-sulfated polymers on the activation kinetics of boar sperm proacrosin to beta-acrosin have been investigated. The aim has been to understand more about the behaviour and function of this protein after it has been released from the acrosome at the time of fertilization. Purified proacrosin was allowed to autoactivate at pH 8.0 in the presence of different concentrations of homologous zona glycoproteins, sulfated polymers (fucoidan, chondroitin sulfates A, B and C, dextran sulfate, polyvinylsulfate and heparin) and non-sulfated polymers (dextran, polyvinylphosphate and hyaluronic acid). Enzyme activity was measured against N-benzoyl-L-arginine p-nitroanalide substrate and changes in molecular mass of the protein monitored by SDS-PAGE. Results show that zona pellucida glycoproteins, fucoidan, dextran sulfate and polyvinylsulfate all potentiate the conversion of proacrosin to beta-acrosin but subsequently inhibit its amidase activity. Dextran, polyvinylphosphate, chondroitin sulfates A, B and C and glucose-6-sulfate, on the other hand, either have no effect on autoactivation and beta-acrosin activity, or enhance it slightly. SDS-PAGE analysis confirmed these observations and further indicated that binding of sulfated polymers to proacrosin inhibited staining by Coomassie Blue. These results are consistent with the hypothesis that binding of zona pellucida glycoproteins and sulfated compounds to proacrosin/acrosin is stereospecific and that contact activation onto soluble 'surfaces' causes conformational changes that are responsible for potentiation or inhibition of activation. The implications of these findings for sperm binding and penetration of the zona pellucida are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Some effects of zona pellucida glycoproteins and sulfated polymers on the autoactivation of boar sperm proacrosin and activity of beta-acrosin. 818 87