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John M. Cavanaugh - One of the best experts on this subject based on the ideXlab platform.
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PhospholipAse A2 sensitivity of the dorsAl root And dorsAl root gAnglion.
Spine, 1998Co-Authors: Srinivasu Kallakuri, John M. CavanaughAbstract:Study Design. This study wAs designed to chArActerize the effects of PhospholipAse A 2 on the neurAl response of dorsAl root And dorsAl root gAnglion in the Anesthetized New ZeAlAnd White rAbbit. Objectives. To exAmine the effects of PhospholipAse A? on the neurAl response of somAtosensory neurons At the dorsAl root gAnglion level. of BAckground DAtA. PhospholipAse A 2 mAy be An irritAting component of disc tissue thAt is present in high concentrAtion in pAinful herniAted discs, in synoviAl fluids, And in serA of rheumAtoid Arthritis pAtients. PhospholipAse A 2 is inflAmmAtory; however, its effects on dorsAl roots And dorsAl root gAnglion response hAve never Deen demonstrAted. Methods. SurgicAlly isolAted dorsAl roots And dorsAl root gAngliA from New ZeAlAnd White rAbbits were investigAted by electrophysiologic techniques. PhospholipAse A 2 doses rAnging from 100 to 400 U were Applied on the mechAnicAllv sensitive segments of the dorsAl root gAngliA, And responses to vArying doses were evAluAted in relAtion to elApsed time. Results. The ApplicAtion of PhospholipAse A 2 on the dorsAl root gAnglion resulted in possible neurotoxicity At doses more thAn 375 U, with no significAnt effect At lower doses except for recruitment of silent units At doses rAnging from 200 to 340 U. Conclusions. PhospholipAse A 2 doses compArAble to serum concentrAtions in humAn rheumAtoid Arthritis AppeAred to be neurotoxic when Applied to dorsAl root gAngliA. At lower doses, silent units become ActivAted thAt were not Active before the PhospholipAse A 2 ApplicAtion. These results suggest thAt dorsAl roots And dorsAi root gAnglion mAy be impAired by PhospholipAse A 2 , leAding to sciAticA And low bAck pAin.
Srinivasu Kallakuri - One of the best experts on this subject based on the ideXlab platform.
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PhospholipAse A2 sensitivity of the dorsAl root And dorsAl root gAnglion.
Spine, 1998Co-Authors: Srinivasu Kallakuri, John M. CavanaughAbstract:Study Design. This study wAs designed to chArActerize the effects of PhospholipAse A 2 on the neurAl response of dorsAl root And dorsAl root gAnglion in the Anesthetized New ZeAlAnd White rAbbit. Objectives. To exAmine the effects of PhospholipAse A? on the neurAl response of somAtosensory neurons At the dorsAl root gAnglion level. of BAckground DAtA. PhospholipAse A 2 mAy be An irritAting component of disc tissue thAt is present in high concentrAtion in pAinful herniAted discs, in synoviAl fluids, And in serA of rheumAtoid Arthritis pAtients. PhospholipAse A 2 is inflAmmAtory; however, its effects on dorsAl roots And dorsAl root gAnglion response hAve never Deen demonstrAted. Methods. SurgicAlly isolAted dorsAl roots And dorsAl root gAngliA from New ZeAlAnd White rAbbits were investigAted by electrophysiologic techniques. PhospholipAse A 2 doses rAnging from 100 to 400 U were Applied on the mechAnicAllv sensitive segments of the dorsAl root gAngliA, And responses to vArying doses were evAluAted in relAtion to elApsed time. Results. The ApplicAtion of PhospholipAse A 2 on the dorsAl root gAnglion resulted in possible neurotoxicity At doses more thAn 375 U, with no significAnt effect At lower doses except for recruitment of silent units At doses rAnging from 200 to 340 U. Conclusions. PhospholipAse A 2 doses compArAble to serum concentrAtions in humAn rheumAtoid Arthritis AppeAred to be neurotoxic when Applied to dorsAl root gAngliA. At lower doses, silent units become ActivAted thAt were not Active before the PhospholipAse A 2 ApplicAtion. These results suggest thAt dorsAl roots And dorsAi root gAnglion mAy be impAired by PhospholipAse A 2 , leAding to sciAticA And low bAck pAin.
Alejandro Alagón - One of the best experts on this subject based on the ideXlab platform.
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A new Affinity Adsorbent for the purificAtion of PhospholipAses A1 And A2 from AnimAl venoms.
Toxicon, 2002Co-Authors: Javier Vargas-villarreal, J.j. Martin-polo, Enrique Reynaud, Alejandro AlagónAbstract:AbstrAct Dimethyl- dl -2,3-disteAroyloxypropyl-2′-hydroxy-ethylAmmonium (RosenthAl's inhibitor) wAs coupled to cArboxyhexyl-SephArose 4B, through cArbodiimide chemistry. PhospholipAse A 2 from HelodermA horridum horridum And CrotAlus AdAmAnteus bind to the immobilized ligAnd in the presence of CA 2+ And cAn be eAsily eluted under Acidic conditions or in the presence of A chelAting Agent, respectively. This Affinity mediA proved to be effective Also in the purificAtion of A CA 2+ -independent PhospholipAse A 1 from vespid venom.
Denis Lebel - One of the best experts on this subject based on the ideXlab platform.
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identificAtion of membrAne dipeptidAse As A mAjor glycosyl phosphAtidylinositol Anchored protein of the pAncreAtic zymogen grAnule membrAne And evidence for its releAse by PhospholipAse A
Biochemical Journal, 1997Co-Authors: Nigel M. Hooper, Sarah Cook, Jean Laine, Denis LebelAbstract:MembrAne dipeptidAse (EC 3.4.13.19) enzyme Activity thAt is inhibited by cilAstAtin hAs been detected in pAncreAtic zymogen grAnule membrAnes of humAn, porcine And rAt origin. Immunoelectrophoretic blot AnAlysis of humAn And porcine pAncreAtic zymogen grAnule membrAnes with polyclonAl AntiserA rAised AgAinst the corresponding kidney membrAne dipeptidAse reveAled thAt the enzyme is A disulphide-linked homodimer of subunit mAss 61 kDA in the humAn And 45 kDA in the pig. Although membrAne dipeptidAse wAs, Along with glycoprotein-2, one of the only two mAjor components of cArbonAte high pH-wAshed membrAnes, no enzyme Activity or immunoreActivity wAs detected in the zymogen grAnule contents. Digestion with bActeriAl phosphAtidylinositol-specific PhospholipAse C (PI-PLC), And subsequent recognition by Antibodies specific for the cross-reActing determinAnt, reveAled thAt membrAne dipeptidAse in humAn And porcine pAncreAtic zymogen grAnule membrAnes is glycosyl-phosphAtidylinositol-Anchored. MembrAne dipeptidAse wAs releAsed from the pAncreAtic zymogen grAnule membrAnes by An endogenous hydrolAse, And the releAsed form migrAted As A disulphide-linked dimer on SDS/PAGE under non-reducing conditions. Under reducing conditions it migrAted with the sAme AppArent moleculAr mAss As the membrAne-bound form, And wAs still A substrAte for bActeriAl PI-PLC. TreAtment of kidney microvillAr membrAnes with PhospholipAse A2 resulted in the releAse of membrAne dipeptidAse in A form thAt demonstrAted electrophoretic And cilAstAtin-SephArose binding properties identicAl to those of the endogenously releAsed form of the enzyme from zymogen grAnule membrAnes. These results indicAte thAt the glycosyl-phosphAtidylinositol Anchor on the pAncreAtic membrAne dipeptidAse is cleAved by An endogenous hydrolAse, probAbly A PhospholipAse A, And thAt this cleAvAge mAy promote the releAse of the protein from the membrAne.
Kouji Nomura - One of the best experts on this subject based on the ideXlab platform.
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role of group iiA PhospholipAse A2 in rAt colitis induced by dextrAn sulfAte sodium
European Journal of Pharmacology, 2003Co-Authors: Yasuhiko Tomita, Hirokuni Jyoyama, Mika Kobayashi, Kenji Kuwabara, Shingo Furue, Masahiko Ueno, Katsutoshi Yamada, Takashi Ono, Isao Teshirogi, Kouji NomuraAbstract:Although group IIA PhospholipAse A(2) hAs been suggested to be implicAted in inflAmmAtory bowel diseAse, its pAthophysiologicAl role in colitis remAins uncleAr. We investigAted whether group IIA PhospholipAse A(2) hAd pro-inflAmmAtory roles in dextrAn sulfAte sodium-induced colitis in the rAt. Secretory PhospholipAse A(2) Activity wAs mArkedly increAsed in the distAl colon with two peAks. Strong immunostAining for group IIA PhospholipAse A(2) wAs found in subepitheliAl tissue And lAminA propriA At eArly stAge And in deeper tissues of the erosion AreA At lAter stAge. TreAtment with A specific group IIA PhospholipAse A(2) inhibitor, S-3013/LY333013 (methyl[[3-(AminooxoAcetyl)-2-ethyl-1-(phenylmethyl)]-1H-indol-4yl]oxy) AcetAte), reduced erosion AreA, shortening of colon And colonic inflAmmAtion, And strongly inhibited the increAse in secretory PhospholipAse A(2) Activity And moderAtely reduced myeloperoxidAse Activity in the colon in vivo, while eicosAnoid levels were not Affected. MArked group IIA PhospholipAse A(2) expression in the erosion AreA And the improvement of colitis by the group IIA PhospholipAse A(2) inhibitor strongly suggest thAt this enzyme plAys pro-inflAmmAtory roles in this colitis model.