Influence of platelet activating factor on gastrointestinal electrical activity and some haematological and clinical parameters in the conscious miniature pig.

The effects of intravenous (i.v.) infusion of platelet-activating factor (PAF), 100 ng/kg/min for 10 min, with and without pretreatment with a selective PAF-antagonist on gastrointestinal electrical activity, arterial pressure and clinical and haematological parameters were studied. Conscious miniature pigs with electrodes implanted in the wall of the antrum pylori and small and large intestine were used. Platelet-activating factor induced restlessness or depression, shivering, tachypnoea and coughing, retching and vomiting, hypotension and a delayed and sustained increase in leucocyte count with an increase in percentage of segmented neutrophils. The PAF-antagonist, SAH 63-675, administered at 10 mg/kg intravenously, inhibited these effects. Platelet-activating factor resulted in a decrease in electrical activity in the antrum and large intestine, whereas small intestinal activity was not significantly influenced. Pretreatment with the antagonist suppressed these inhibitory effects.