The effects of intracoronary prostaglandin E1 (PGE1) in doses of 2.3 or 7.6 μg/min on hyperaemic responses after 15 sec, 30 sec, 60 sec and 120 sec occlusions were studied at constant pressure (CP) or constant volume (CV) perfusion on the isolated fibrillating dog heart. Basal perfusion pressure was maintained at 150 mm Hg. During PGE1 administration, coronary flow and conductance increased but the postocclusion reaction decreased proportionally to the doses, on both CP and CV perfusion. PGE1 was more effective on CV than on CP perfusion, therefore the differences between the postocclusion reactions found in the control state due to the different perfusion techniques disappeared during the application of PGE1. The results are compatible with the prostaglandin hypothesis of reactive hyperaemia, but as PGE1 cannot elicit such marked vasodilatation as does occlusion, other factors (metabolic, myogenic, physical) too may be involved in the development of hyperaemic reaction. It is improbable that the effect of PGE1 should result only from a decrease in coronary dilatation reserve.
|Number of pages||15|
|Journal||Acta physiologica Academiae Scientiarum Hungaricae|
|Publication status||Published - Jan 1 1977|
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