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Objective: Earlier, we reported that high insulin incubation in vitro leads to increased ETA receptor expression in cultured rat aortic smooth muscle cells (Diabetes 1998, 47: 934–944). Our later observation of enhanced endothelin-1 evoked vasoconstriction in aorta from the hyperinsulinemic obese Zucker rat indicated that this interaction might also be relevant in vivo. To further examine the relationship between insulinemia and endothelin, we characterized endothelin receptor expression and endothelin-1 peptide levels in vascular tissues and plasma from young and old obese Zucker rats. Methods: 12 and 40-week-old Zucker obese and lean rats were used. Plasma endothelin-1 levels and endothelin-1 peptide content in the mesenteric artery and in the thoracic aorta were examined by radioimmunoassay. Messenger RNA levels of endothelin-1 peptide and ETA and ETB receptors were examined in the aortic and mesenteric vessels using RT-PCR. Results: Obese rats from both age groups had significantly higher plasma levels of insulin (4–10 fold), total cholesterol (2–3 fold), triglycerides (10-fold), and glucose (∼1.5 fold) than their lean counterparts. There was a trend toward worsening lipoproteinemia and glycemia, but improved insulinemia with age in the obese rats. In association with these changes, obese rats exhibited attenuated endothelin-1 peptide and preproET-1 mRNA levels, but conversely elevated ETA and ETB receptor mRNA levels in both aortic and mesenteric vessels. Conclusion: These data suggest that vascular tissue from the metabolically dysregulated obese Zucker rat exhibits attenuated endothelin-1 peptide production and elevated endothelin receptor levels. Since elevated insulin levels have been linked to increased endothelin receptor expression, it is plausible that hyperinsulinemia upregulates endothelin receptors contributing to elevated vasoconstrictor responses to endothelin-1 in this model of obesity and hypertension. [ABSTRACT FROM PUBLISHER]

We have reported previously that liver X receptor-alpha (LXRalpha) can mediate a novel cAMP-dependent increase in renin and c-myc gene transcription by binding as a monomer to a unique regulatory element termed the cAMP-negative response element (CNRE). To determine whether this novel action of LXRalpha has global implications on gene regulation, we employed expression profiling to identify other genes regulated by this unique mechanism. Here we report the existence of a set of known and unknown transcripts regulated in parallel with renin. Querying the Celera Mouse Genome Assembly revealed that a majority of these genes contained the consensus CNRE. We have confirmed the functionality of these CNREs by competition for LXRalpha binding via electrophoretic mobility shift assays (EMSA) and by the use of CNRE decoy molecules documenting the abolishment of the cAMP-mediated gene induction. Taken together, these results demonstrate that the interaction between cAMP-activated LXRalpha and the CNRE enhancer element is responsible for widespread changes in gene expression and identify a set of LXRalpha/cAMP-regulated genes that may have important biological implications.

AstraZeneca (formerly Astra) is developing ximelagatran, an orally active thrombin inhibitor and prodrug of melagatran, for the potential prevention and treatment of venous thromboembolism (VTE) in hip and knee replacement, for prevention of stroke in atrialfibrillation (AF) and for post acute coronary syndrome. As of December 1999, the compound was undergoing phase III trials for the prevention of VTE [349551]; these were ongoing in December 2001. By December 2000, ximelagatran had entered phase III trials for the prevention of stroke in atrial fibrillation [395212]. In September 2000, the company expected global NDA filing for this indication to take place in the middle of 2001 [383469]; however, in December 2000 this was revised to the second half of 2002 [395212], and in March 2001, to the second quarter of 2003 [402040], [416882], [431673]. By December 2000, a phase II trial was underway of ximelagatran as a potential treatment following myocardial infarction [395237]. In December 2001, early phase clinical trials were ongoing for post acute coronary syndrome [431673]. By December 2001, EU and US filings for VTE prevention were anticipated in the third quarter of 2002 and the second quarter of 2003, respectively [3144721, [350050], [431673]. Exanta is the trade name for both melagatran and ximelagatran. In 1998, marketing of ximelagatran in the US was to be assigned to the Astra/Merek joint marketing venture, prior to the merger [276577]. In April 1999, ABN predicted sales of 4 pounds million in 2003 [328676], [394606]. In December 2000, Lehman Brothers estimated peak sales to be $1.4 billion [394606]. At the same time, ABN-AMRO predicted peak sales of more than $1 billion [395237]. In June 2000, Deutsche Bank predicted sales of $70 million in 2002, rising to $245 million in 2003 [374500]. In September 2000, Merrill Lynch predicted sales of 125 pounds million in 2002, rising to 625 pounds million in 2004 [383742]. In February 2001, Merrill Lynch estimated that peak sales would reach $924 million in 2005 [429697].