ROLE OF FREE-RADICALS AND PLATELET-ACTIVATING-FACTOR IN THE GENESIS OF INTESTINAL MOTOR DISTURBANCES INDUCED BY ESCHERICHIA-COLI ENDOTOXINS IN RATS
ROLE OF FREE-RADICALS AND PLATELET-ACTIVATING-FACTOR IN THE GENESIS OF INTESTINAL MOTOR DISTURBANCES INDUCED BY ESCHERICHIA-COLI ENDOTOXINS IN RATS
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DOI：
10.1016/0016-5085(91)90268-p
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发表时间：
1991-04-01
期刊：
影响因子：
29.4
通讯作者：
BUENO, L
中科院分区：
文献类型：
--
作者：
PONS, L;DROYLEFAIX, MT;BUENO, L
The effects of IV administration ofEscherichia coliendotoxin on intestinal myoelectric activity was investigated in conscious fasted rats chronically implanted with nichrome electrodes in the duodenojejunum. These effects were compared with those of platelet-activating factor and were evaluated in animals pretreated with a specific platelet-activating factor antagonist, BN 52021, indomethacin, a selective prostaglandin E2antagonist, SC 19220, and several free radical scavengers. Intravenous administration of endotoxin (E. coliS.O111:B4) at a dose of 50 μg/kg suppressed the migrating myoelectric complexes, which were replaced by continuous rhythmic clusters of rapidly propagated spike bursts for 114.7 ± 19.9 minutes. Intraperitoneal plateletactivating factor (25 μg/kg) also inhibited the migrating myoelectric complex pattern for 146.1 ± 24.1 minutes. Previous IV administration of BN 52021 (50 mg/kg−1) abolished the motor alterations induced by platelet-activating factor and significantly reduced to 43.1 ± 12.2 minutes those induced by endotoxin (P< 0.01). Indomethacin (10 mg/kg IP), injected before endotoxin or platelet-activating factor, also significantly reduced the duration of migrating myoelectric complex inhibition to 45.6 ± 7.8 and 47.7 ± 8.3 minutes, respectively (P< 0.01). SC 19220 significantly reduced the effects of platelet-activating factor from 151.8 ± 26.4 to 67.4 ± 14.7 min (P< 0.01). Superoxide dismutase (15,000 U/kg IV) injected before either endotoxin or platelet-activating factor shortened the migrating myoelectric complex inhibition to 45.7 ± 9.9 and 72.9 ± 10.4 minutes, respectively (P< 0.01). Allopurinol and dimethylsulfoxide administered orally at 50 mg/kg 1 hour before endotoxin reduced the migrating myoelectric complex inhibition to 42.5 ± 6.5 and 38.2 ± 6.4 minutes, respectively (P< 0.01). They also reduced platelet-activating factor-induced intestinal myoelectric alterations to 68.5 ± 10.6 and 31.7 ± 6.1 minutes, respectively (P< 0.01). It is concluded that endogenous release of platelet-activating factor is partly responsible for the intestinal motor alterations induced by endotoxin, these effects being also mediated through the release of prostaglandins and free radicals. However, prostaglandins, as well as free radicals, appear to be partly involved in the platelet-activating factor-induced action ofE. coliendotoxin on intestinal motility.
