1 This study was undertaken to characterize pharmacologically the prostanoid receptor subtypes mediating contraction in human umbilical vein (HUV). 2 HUV rings were mounted in organ baths and concentration -response curves to U-46619 (TXA 2 mimetic) were constructed in the absence or presence of SQ-29548 or ICI-192,605 605 (100 nm) was completely ineffective against PGF 2a or fluprostenol. In addition, lack of antagonistic effect of AH 6809 (1 mm) against PGF 2a was observed. 5 In conclusion, the findings obtained with TP-selective agonist and antagonists provide strong evidence of the involvement of TP receptors promoting vasoconstriction in HUV. Furthermore, the action of the natural and synthetic EP receptor agonists appears to be mediated via TP receptors. On the other hand, the results employing FP receptor agonists and antagonists of different prostanoid receptors suggest the presence of FP receptors mediating vasoconstriction in this vessel.

No abstract