Thromb Haemost 1991; 65(03): 296-299
DOI: 10.1055/s-0038-1648138
Original Article
Schattauer GmbH Stuttgart

In Vivo Antiaggregatory Action of Platelet-Activating Factor in Beagle Dogs: Role for Prostacyclin

Ferenc Hermán
The Department of Pharmacodynamics and Pathophysiology, Semmelweis University Medical School, Budapest, Hungary
,
Kálmán Magyar
The Department of Pharmacodynamics and Pathophysiology, Semmelweis University Medical School, Budapest, Hungary
,
János G Filep
The Department of Pharmacodynamics and Pathophysiology, Semmelweis University Medical School, Budapest, Hungary
› Author Affiliations
Further Information

Publication History

Received: 26 June 1990

Accepted after revision 26 October 1990

Publication Date:
02 July 2018 (online)

Summary

The effects of platelet-activating factor (PAF) on in vivo platelet aggregation were studied in anaesthetized beagle dogs by using the extracorporeal filter-loop technique. Intraarterial administration of PAF caused an immediate increase in filter pressure, indicating enhanced in vivo platelet aggregation. Intravenous administration of PAF (3-100 ng kg−1) resulted in a transient dose-dependent inhibition of spontaneous platelet aggregation on the filter with concomitant elevation in plasma 6-keto-PGF levels. These changes were significantly attenuated by pretreatment of the animals either with BN 52021 (4 mg kg−1), a specific PAF receptor antagonist or with acetylsalicylic acid (25 mg kg−1). Intraarterial infusion of exogenous prostacyclin at concentrations similar to those observed following intravenous PAF administration, resulted in a transient inhibition of the spontaneous platelet aggregation. These data provide evidence for prostacyclin release in response to PAF, and suggest that prostacyclin may mediate the in vivo anti-aggregatory action of PAF in anaesthetized dogs.