Here, we show that PGD(2) biosynthesis is augmented during platelet activation in humans and, although vascular expression of DP1 is conserved ABT-737 concentration between humans and mice, platelet DP1 is not present in mice. Despite this, DP1 deletion in mice augmented aneurysm formation and the hypertensive response to Ang II and accelerated atherogenesis and thrombogenesis. Furthermore, COX inhibitors in humans, as well as platelet depletion, COX-1 knockdown,

and COX-2 deletion in mice, revealed that niacin evoked platelet COX-1-derived PGD(2) biosynthesis. Finally, ADP-induced spreading on fibrinogen was augmented by niacin in washed human platelets, coincident with increased thromboxane (Tx) formation. However, in platelet-rich plasma, where formation selleck of both Tx and PGD(2) was increased, spreading was not as pronounced and was inhibited by DP1 activation. Thus, PGD(2), like PGI(2), may function as a homeostatic response to thrombogenic and hypertensive stimuli and may have particular relevance as a constraint on platelets during niacin therapy.”
“Eastern hemlock (Tsuga canadensis [L.] Carr.) is an ecologically important tree species experiencing severe mortality across much of its eastern

North American distribution, caused by infestation of the exotic hemlock woolly adelgid (Adelges tsugae Annand). STI571 Protein Tyrosine Kinase inhibitor To guide gene conservation strategies for this imperiled conifer, we conducted a range-wide genetic variation study for eastern hemlock, amplifying 13 highly polymorphic nuclear microsatellite loci in 1,180 trees across 60 populations. The results demonstrate that eastern hemlock exhibits moderate inbreeding, possibly a signature of a prehistoric decline associated with a widespread insect outbreak. Contrary to expectations, populations in formerly glaciated regions are not less genetically diverse than in the putative southern refugial region. As expected, peripheral disjunct populations are less genetically diverse than main-range populations, but some are highly genetically differentiated or contain unique

alleles. Spatially explicit Bayesian clustering analyses suggest that three or four Pleistocene glacial refuges may have existed in the Southeastern United States, with a main post-glacial movement into the Northeast and the Great Lakes region. Efforts to conserve eastern hemlock genetic material should emphasize the capture of broad adaptability that occurs across the geographic range of the species, as well as genetic variability within regions with the highest allelic richness and heterozygosity, such as the Southern Appalachians and New England, and within disjunct populations that are genetically distinct. Much genetic variation exists in areas both infested and uninfested by the adelgid.