Comparison of umbilical vein models for measurement of relative prostacyclin and thromboxane production.
There is growing evidence that blood vessels generate TXA2 in addition to PGI2. We examined effluents from continuously perfused human umbilical vein and supernatants from umbilical vein rings for TXB2 and 6-keto-PGF1 alpha measurements (stable metabolites of TXA2 and PGI2, respectively). TXB2 and 6-keto-PGF1 alpha were identified in all samples. 6-keto-PGF1 alpha to TXB2 ratio was higher in intact vein effluents than in the venous ring supernatants (112:1 and 28:1, respectively, P less than 0.01). Arachidonate stimulation increased 6-keto-PGF1 alpha and TXB2 levels similarly in the intact vein effluent. In contrast, stimulation of the venous rings resulted in a relatively larger increase in TXB2 than in 6-keto-PGF1 alpha. This caused 6-keto-PGF1 alpha to TXB2 ratio to decline (p less than 0.01). The identity of TXB2 was confirmed in several different ways. These data suggest that 1) human umbilical veins produce TXA2 in addition to PGI2, 2) TXA2 release is more by venous rings than by the intact vein probably reflecting contribution from non-endothelial layers, and 3) arachidonate stimulation causes relatively greater release of TXA2 than of PGI2 from the venous rings, whereas release of PGI2 and TXA2 is similar from the intact vein.
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology; D011464:Epoprostenol / Q000096:biosynthesis*; D006801:Humans; D008689:Methacrylates / Q000494:pharmacology; D008954:Models, Biological; D011453:Prostaglandins / Q000096:biosynthesis*; D013048:Specimen Handling; D013928:Thromboxane A2 / Q000096:biosynthesis*; D013929:Thromboxane B2 / Q000096:biosynthesis; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors; D013931:Thromboxanes / Q000096:biosynthesis*; D014471:Umbilical Veins / Q000378:metabolism*
D001095:Arachidonic Acids; D008689:Methacrylates; D011453:Prostaglandins; D013931:Thromboxanes; D016718:Arachidonic Acid; D013929:Thromboxane B2; D013928:Thromboxane A2; D015121:6-Ketoprostaglandin F1 alpha; C031517:2-methyl-3-(4-(3-pyridinylmethyl)phenyl)-2-propenoic acid; D011464:Epoprostenol; D013930:Thromboxane-A Synthase; D001241:Aspirin