Rat kidney thromboxane receptor: molecular cloning, signal transduction, and intrarenal expression localization.

EP1‐ and FP‐mediated cross‐desensitization of the alpha (α) and beta (β) isoforms of the human thromboxane A2 receptor

“…While the precise intrarenal distribution of the FP has not yet been reported, in situ hybridization has localized the EP 1 largely to the cortical collecting duct (Hebert et al, 1991;Hebert, 1994). Similarly, in situ hybridization studies in the rat confirmed the abundant expression of the TP within the glomerulus, arterioles and epithelium lining the urinary pelvis and an absence of/reduced expression in the proximal tubule, cortical thick limb or the collecting duct (Abe et al, 1995). However, despite this knowledge, the relative roles of the individual EP 1 , FP and TP prostanoid receptors within the kidney remain largely unknown and the significance of two TP isoforms, namely TPa and TPb, to renal function in humans remains to be investigated.…”

Thromboxane A2 Signalling in Humans: a ‘Tail’ of Two Receptors

“…Reverse transcriptase polymerase chain reaction (RT PCR) experiments indicated that HUVECs express only TPβ [32] whereas human platelets were reported to express both TPα and TPβ isoforms [33]. The physiologic significance for the existence of 2 receptors for TXA 2 in humans, but not in other species thus far investigated [21][22][23][24][25], is currently unknown but is an area of extensive research interest within my laboratory.…”

“…A cDNA for the human TXA 2 receptor (TP) was originally cloned from placenta and the platelet like MEG-01 cell line [20] and since then cDNAs for TPs from a number of species have been cloned and characterised [21][22][23][24][25]. All TPs are predicted to share the seven α-helical transmembrane domain arrangement typical of other members of the GPCR superfamily [26].…”

DMSO inhibits human platelet activation through cyclooxygenase-1 inhibition. A novel agent for drug eluting stents?

“…Thromboxane A2 is a potent platelet activating eicosanoid synthetised from COX-dependent endoperoxides [2] and its inhibition has been proposed as a novel approach to prevent stent thrombosis [37]. To identify the possible mediator of altered thromboxane A2 levels, total COX activity was assayed.…”