[The involvement of prostaglandins in the inhibiting effect of endotoxin on the myoelectric activity of the gastrointestinal system in pigs].

The probable involvement of prostaglandins in the myoelectrical response of the antrum pylori and small intestine to endotoxin (LPS) was studied in the piglet. In these experiments the influence of I.V. infusion of PGF2 alpha and PGE2 and of I.V. injection of LPS, without and with indomethacin (INDO) pretreatment, on myoelectrical activity of the antrum pylori, duodenum, jejunum and ileum as well as on some clinical and haematological parameters was studied. Infusion of the 2 PG's, especially PGE2, inhibited myoelectrical activity of the antrum pylori. PGE2 also reduced duodenal activity. PGF2 alpha was without effect on duodenal and jejunal activity, but stimulated ileal activity. Both PG's induced fever, nausea, vomiting and sedation or excitation. With the higher dose of PGE2 diarrhoea was also observed. Injection of LPS induced identical myoelectrical and clinical changes, as described for PGE2. However, endotoxin did not induce diarrhoea. Depending on the dose, administration of LPS resulted in a leukocytosis or a leukopenia together with an increase in band neutrophils. Following pretreatment with INDO the effects of LPS on gastrointestinal electrical activity were reduced and its clinical symptoms were nearly completely inhibited. The haematological changes induced by LPS, however, were not influenced by INDO. These experiments suggest a possible involvement of the PG's in the clinical symptoms and in the initial inhibitory effect of LPS on myoelectrical activity especially of the antrum. However, the induced haematological changes are probably not mediated by the arachidonic acid pathway.