[Plasma thromboxane B2 and capacity of the aorta to produce prostacyclin in arteriopathies of the lower extremities].

Plasma levels of thromboxane B2, and 6-Keto-PGF1 alpha, stable metabolites of thromboxane and of prostacyclin were determined by radioimmunoassay in 17 patients with arterial disease and 10 control subjects. The production of prostacyclin from incubates of aortic microsomal fractions of patients was also studied. There was a significant elevation of thromboxane B2 in the peripheral venous blood of patients with arterial lesions (142 +/- 152 pg/ml vs 22 +/- 2 pg/ml, p less than 0.005); levels of 6-KetoPGF1 alpha were equally low in controls and patients. Rate of production of prostacyclin, which was 450 +/- 24 pmol/50 mg of proteins in 10 minutes in controls, was reduced to 97 +/- 86 pmol/50 mg prot. 10 min (p less than 0.01) in patients. Co-existence of raised plasma thromboxane levels and a reduced capacity for prostacyclin synthesis in the same patients is supportive evidence of the thrombogenic theory of arterial disease.