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The effect of a prostaglandin DP‐receptor partial agonist (192C86) on platelet aggregation and the cardiovascular system in healthy volunteers.
Author(s) -
Gray SJ,
Giles H.,
Posner J.
Publication year - 1992
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1111/j.1365-2125.1992.tb05641.x
Subject(s) - agonist , platelet , volunteer , receptor , vasodilation , medicine , chemistry , endocrinology , prostaglandin , blood pressure , prostacyclin , pharmacology , biology , agronomy
1. PGD2 (DP)‐receptors mediate inhibition of platelet aggregation and vasodilatation. If receptor reserve were greater on platelets it might be possible to separate these effects. To determine whether such a difference in receptor reserve exists, we have examined the effects of a highly selective DP‐receptor partial agonist 192C86 on platelet aggregation and the cardiovascular system in healthy volunteers. 2. Using an open, dose‐escalating study design, four male volunteers received constant rate intravenous infusions of 192C86 for up to 60 min. Ex vivo platelet aggregation to ADP and collagen in platelet‐rich plasma (PRP) and whole blood (WB) was studied at baseline, after 15, 30 and 60 min of each infusion and at 180 min post‐infusion. Heart rate (HR), systolic and diastolic (DBP) blood pressure were measured at frequent intervals. Adverse experiences were monitored by checklist. Facial flushing was assessed by the volunteer using a visual analogue scale, by an observer using a numerical scale and by full‐face colour photographs. Blood was taken for assay of plasma 192C86 concentrations by radio‐immunoassay (r.i.a.). 3. 192C86 (0.007‐0.058 micrograms kg‐1 min‐1) inhibited platelet aggregation to ADP and collagen both in PRP and WB in a dose‐dependent manner. However, this was always accompanied by a decrease in DBP, increase in HR and facial flushing. Plasma concentrations of 192C86 were at or below the limits of sensitivity of the r.i.a. (0.5 ng ml‐1). 4. The highest infusion rate was stopped after 20 min due to symptomatic hypotension on standing.(ABSTRACT TRUNCATED AT 250 WORDS)