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)

A mechanism of writhing reaction induced by kaolin, a known activator of factor XII, was studied. Kaolin induced a distinct writhing response, when injected intraperitoneally into mice (2.5 mg/mouse). The response disappeared in 15 min, but it was reproduced by intraperitoneal injection of captopril, 20 micrograms, into mice who had received the injection of kaolin 60 min before. This later response as well as the early one was not produced when mice were pretreated with bromelain (10 mg/kg, intravenously), 30 min before the kaolin administration. Therefore we determined if bromelain, a known depleter of plasma prekallikrein and a high molecular weight (HMW) kininogen, depletes those in mice. Plasma was collected from mice with or without pretreatment of bromelain, and kinin release of these plasma samples was examined by action of kaolin. The bromelain-treated mouse plasma released kinin amount of less than detection limit when activated with kaolin, whereas normal plasma released about 300 ng/ml of kinin of bradykinin equivalent as assessed by rat uterus contraction. Furthermore, activation of prekallikrein by kaolin was observed in mouse plasma as amidase activity to produce fluorescence from the synthetic substrate. It was completely diminished in the presence of soybean trypsin inhibitor. These results suggest that bromelain could deplete the HMW-kininogen in mouse plasma in the same way as in rat plasma. Furthermore, it is assumed that the kinin released from HMW-kininogen by kaolin could be responsible for inducing the writhing response.
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PMID:Kaolin-induced writhing response in mice: activation of the plasma kallikrein-kinin system by kaolin. 261 39

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