Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.32 (bromelain)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prekallikrein activity in plasma was assayed using a synthetic peptidyl fluorogenic substrate (carbobenzoxy-L-phenylalanyl-L-arginine 4-methylcoumarinyl-7-amide), after activation of prekallikrein by acetone and kaolin. For total kininogen assay, the pretreatment of plasma at pH 2.0 was the best to eliminate bradykinin potentiators and kininase activity, before addition of trypsin to convert kininogen to bradykinin. Assay method of high molecular weight (HMW) kininogen was established by conversion of HMW-kininogen to bradykinin through activation of Hageman factor by glass powder and that of low molecular weight (LMW) kininogen was also by treatment of HMW-kininogen-depleted plasma in the same way as that for total kininogen. The marked reduction of prekallikrein and HMW-kininogen, not of LMW-kininogen, was found in pleural fluid of rat carrageenin pleurisy, and in plasma after i.v. injection of bromelain in rats. Members of the pedigree of hereditary angioneurotic edema patients also show low levels of prekallikrein and kininogens in plasma.
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PMID:Assay methods for prekallikrein and kininogens and their applications. 49 7

Pleurisy was induced in rats by an intrapleural injection of 0.5 ml of 1% kaolin. The exudation of plasma into the pleural cavity showed two peaks at 20 min and 3-5 h after the kaolin injection. The volume of the pleural fluid increased gradually up to 5 h. The effects of treatment with mepyramine, methysergide, captopril, bromelain and indomethacin suggested that the early phase (20 min) of exudation was mediated mainly by kinins, histamine and 5-HT, and that the late phase (3 h) was mediated by prostaglandins (PGs) and possibly kinins. We measured the levels of histamine, kinin and PG in the pleural exudate to verify the involvement of the mediators mentioned above. Intracellular histamine levels decreased markedly and extracellular histamine levels increased significantly 20 min after the induction of kaolin pleurisy. Only threshold levels of kinin were detected after the induction of pleurisy. Captopril treatment, however, increased kinin levels which peaked at 20 min and decreased rapidly thereafter. Levels of 6-keto-PGF1 alpha and thromboxane B2 showed a peak at 20 min, whereas levels of PGE2 increased gradually from 20 min to 5 h. These results indicate that kaolin-induced pleurisy is a kinin-related inflammation and could be used as a model for studying the in vivo interaction of the kallikrein-kinin system and PGs at inflammatory sites.
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PMID:Time course analyses of kinins and other mediators in plasma exudation of rat kaolin-induced pleurisy. 306 90

The levels of high molecular weight (HMW) kininogen and pre-kallikrein in rat plasma were markedly reduced after single injection of bromelain (10 mg/kg, i.v.) and gradually recovered over a 72 hour period. The level of low molecular weight (LMW) kininogen, however, was not changed during this period. Rat pleurisy was induced by intrapleural injection of lambda-carrageenin. The levels of HMW kininogen and prekallikrein, but not of LMW kininogen, in the exudate were markedly decreased, when compared with those in plasma of the same animals. After pretreatment with disulfiram, oral administration of ethanol (2 g/kg) or intravenous injection of acetaldehyde (10 mg/kg) to rats caused significant decrease in the plasma level of LMW kininogen with no significant effect on the plasma HMW kininogen and prekallikrein levels. These results suggest that HMW and LMW kininogens may be consumed separately in vivo and play different roles.
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PMID:Independent consumption of high and low molecular weight kininogens in vivo. 381 86

A mode of interaction of bradykinin with prostaglandins (PGs) in pain were compared with that in acute inflammation. When pain production was measured as an increase in reflex hypertensive response of the lightly anesthetized dogs after intrasplenic injection of bradykinin, the response was dependent to the doses (0.3-5 nmol) of bradykinin and that by the small doses (0.1-1 nmol) was blocked by intrasplenic infusion of indomethacin (0.54 mumol/min). The response to the threshold dose of bradykinin (0.3 nmol), which was suppressed during the indomethacin infusion, was potentiated by simultaneous injection of exogenous PGs. Order of the potency was PGI2 greater than PGH2 greater than PGE2 = TXA2 much greater than PGD2. Thus, it is clear that bradykinin induced pain through the generation of one of prostaglandins. On the other hand, the activity of bradykinin in plasma leakage was potentiated by simultaneous injection of PGE2, when tested in rabbit skin. In rat carrageenin-induced pleurisy, plasma prekallikrein was activated and high molecular weight (HMW) kininogen, not low molecular weight (LMW) kininogen, was consumed in the pleural cavity in the entire course of the pleurisy. Bradykinin played a role in plasma exudation in the pleurisy, because the plasma leakage was markedly inhibited in the rats, in which prekallikrein and HMW kininogen in plasma were depleted by intravenous bromelain. PGE2 was found in the pleural exudate, but the contribution of PGE2 itself to the plasma exudation seems to be only 10%. On the basis of the bradykinin release in the pleural cavity, once the PGE2 release was superimposed, the maximal plasma leakage was observed, indicating that PGE2 was released independently from bradykinin, and potentiated the plasma leakage by bradykinin.
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PMID:Different modes of interaction of bradykinin with prostaglandins in pain and acute inflammation. 381 4

Rat pleurisy was induced by intrapleural injection of 0.1 ml of 1% kaolin or 1% croton oil, and the time courses of pleural fluid accumulation and white cell migration were examined. Peak pleural fluid accumulation was observed at respectively 5 and 16 h after the inciter injection. Migration of white cells into the pleural cavity showed a peak at respectively 7 or 24 h after each inciter. Polymorphonuclear leukocytes were predominant in pleural cells of kaolin pleurisy at 3 h, while in croton-oil pleurisy the major white cells were mononuclear cells and lymphocytes at 3 h, and polymorphonuclear leukocytes appeared later around 16 h. Pretreatment with several agents modified both types of induced pleurisy. Kaolin pleurisy at 3 h was suppressed by indomethacin, mefenamic acid, paramethasone, bromelain and soy-bean trypsin inhibitor, while croton oil pleurisy at 3 h was suppressed significantly by indomethacin and paramethasone.
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PMID:Rat pleurisy induced by kaolin or croton oil: time course of fluid accumulation and white cell migration. 405 63

Rat pleurisy was induced by intrapleural injection of lambda-carrageenin. The pleural exudate began to be accumulated 1-3 h after carrageenin administration and showed a peak at 19 h. The levels of prekallikrein and high-molecular-weight (HMW), but not low-molecular-weight (LMW), kininogen in the pleural fluid were markedly decreased when compared with those in plasma. Prekallikrein in rat plasma was activated by incubation with carrageenin in vitro. Captopril increased the plasma exudation significantly at 1-5 h. Depletion of prekallikrein and HMW kininogen in rat plasma by preadministration of bromelain caused marked inhibition of the plasma exudation at 1-24 h. The rest of the plasma exudation after bromelain was further decreased by simultaneous pretreatment of rats with both bromelain and aspirin. These results clearly indicate that plasma prekallikrein was activated in the pleural cavity and bradykinin released was responsible for plasma exudation during the entire course of this pleurisy.
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PMID:Activation of plasma kallikrein-kinin system and its significant role in pleural fluid accumulation of rat carrageenin-induced pleurisy. 634 79

1. Effects of an orally active non-peptide (BK) B2 receptor antagonist, FR173657 ((E)-3-(6-acetamido-3-pyridyl)-N-[N-[2,4-dichloro-3-[(2-methyl-8-quinoli nyl) oxymethyl]phenyl]-N-methylaminocarbonylmethyl] acrylamide) on the plasma exudation in rat carrageenin-induced pleurisy were investigated. 2. Plasma exudation induced by intrapleural injection of bradykinin (BK, 3 nmol per rat) into male SD strain rats (SPF, 8 weeks old) were significantly inhibited by oral administration of novel B2 receptor antagonist FR173657 (3-30 mg kg-1, 1 h before BK injection) in a dose-dependent manner, whereas that induced by histamine was not. 3. The inhibitory effect of 30 mg kg-1 FR173657 persisted for more than 4 h. 4. Intrapleural injection of lambda-carrageenin (2% (w/v), 0.1 ml per rat) caused marked plasma exudation and accumulation of exudates from 1 h after carrageenin injection. The maximum plasma exudation response was observed 5 h after carrageenin. The oral administration of FR173657 to rats (30 mg kg-1, 1 h before carrageenin) significantly (by 50-77%) blunted the plasma exudation 1, 3, 5, and 7 h after carrageenin, causing a significant parallel reduction (by 42-57%) in the volume of exudates. 5. The anti-inflammatory effect of FR173657 on rat carrageenin-induced pleurisy was almost equipotent with that of the peptide B2 antagonist Hoe140 (1 mg kg-1, i.v.), a plasma kallikrein inhibitor, soy bean trypsin inhibitor (0.3 mg per rat, intrapleural injection) and bromelain (10 mg kg-1, i.v.). 6. In pleurisy induced by intrapleural injection of a histamine releaser, compound 48/80, the plasma exudation was observed only within 20 min after the injection. This plasma exudation was not affected by FR173657, although it was completely inhibited by a mixture of pyrilamine (5 mg kg-1, i.v.) and methysergide (3 mg kg-1, i.v.). 7. These results indicate that FR173657 is an orally active, promising anti-inflammatory agent for kinin-dependent inflammation.
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PMID:Effects of an orally active non-peptide bradykinin B2 receptor antagonist, FR173657, on plasma exudation in rat carrageenin-induced pleurisy. 920 40