In this study it is reported that: (1) the levels of blood
platelet-activating factor and serum tumour necrosis factor
significantly increased after coronary ligation and reperfusion,
compared with sham-ligated controls, in an anaesthetized rat model;
(2) compared with vehicle controls, pretreatment with the PAF
antagonist BN 50739 (10 mg/kg, i.v.) produced significant
decreases in infarct size (from 29.6 ± 4.0% to 22.4
± 2.1%, p<0.05 after 3 h ligation, and from
28.5 ± 9.5% to 10.5 ± 4.5%,
p<0.01 after 4 h reperfusion) and the level of serum TNF (from 10.4
± 7.7 U/ml to 3.9 ± 4.8 U/ml, p<0.05); and (3) a significan positive correlation was found between the
level of blood PAF or serum TNF and infarct size. The present
results indicate that PAF and TNF may be important mediators
involved in myocardial ischaemia and reperfusion injury, and that
PAF antagonists may exert a protective effect on ischaemic or
reperfused myocardium by inhibiting the interaction of PAF and TNF.
