Regional variability of prostacyclin biosynthesis.

To investigate the regional variability in arterial and venous endothelial prostacyclin (PGI2) biosynthesis, we obtained 1-cm segments of carotid arteries, external jugular veins, femoral arteries and veins, iliac arteries and veins, inferior venae cavae (IVC), and aortas from 17 dogs. Vessel luminal PGI2 production was measured in the basal state by radioimmunoassay of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). A total of 90 arterial specimens (57, 19, and 14 segments, respectively, of femoral/carotid arteries, iliac arteries, and aorta) and 41 venous specimens (15, 10, and 16 segments, respectively, of femoral/jugular veins, iliac veins, and IVC) were analyzed. Overall, arterial endothelial 6-keto-PGF1 alpha was higher than venous (8.1 +/- 0.5 ng/ml vs. 4.9 +/- 0.7 ng/ml, p less than 0.0004); 6-keto-PGF1 alpha levels were greater in the arteries than in their corresponding veins [femoral/carotid arteries (6.3 +/- 0.4 ng/ml) vs. femoral/jugular vein (2.1 +/- 0.4 ng/ml), p less than 0.0002; iliac arteries (9.3 +/- 1.0 ng/ml) vs. iliac veins (4.8 +/- 0.9 ng/ml), p less than 0.005; aorta (14.0 +/- 1.6 ng/ml) vs. IVC (7.5 +/- 1.4 ng/ml), p less than 0.006].(ABSTRACT TRUNCATED AT 250 WORDS)