[Endogenous prostacycline and coronaropathy. Plasma levels of 6-keto-PGF1 alpha]

Prostacycline may play a preventive role in the development of ischaemic complications of coronary atherosclerosis through its vasodilatory and platelet antiaggregant properties. Its biological instability makes it difficult to measure in the plasma; however, it is possible to determine plasma concentrations by radioimmune assay of one of its stable derivatives, 6-Keto-prostaglandin F1 alpha (6KPGF1 alpha). Systemic plasma concentrations at rest of 30 patients with severe atherosclerosis were not significantly different from those of healthy control subjects (7.5 +/- 6.5 vs 10 +/- 5 pg/ml). In addition ischaemia during exercise is not associated with significant variations; at rest 7.1 +/- 6 pg/ml in the "ischaemic" group (n = 20) compared to 7.6 +/- 6.4 pg/ml in the "non-ischaemic" group (n = 10); on effort: 9 +/- 10 pg/ml compared to 13.3 +/- 14 pg/ml. These results show that measuring the plasma 6KPGF1 alpha by peripheral vein blood sampling is of no use in the diagnosis of coronary atherosclerosis or of myocardial ischaemia on effort.