Nitroglycerin and nitroprusside are known to differ in their relative degree of systemic arterial and venous dilation. Nitroglycerin has been shown to be a potent large-vessel coronary dilator, but the effects of nitroprusside on coronary artery size are unclear. Accordingly, we studied coronary artery angiographic responses to both nitroprusside and nitroglycerin in 12 patients. Diameters Of left coronary artery segments were measured by quantitative angiography before and during an intravenous infusion of nitroprusside and after sublingual nitroglycerin when both drugs were administered in doses adjusted to achieve reductions in aortic pressure. Dilation of the left coronary artery was observed after nitroprusside and after nitroglycerin. Degrees of dilation were similar in the various left coronary artery segments after either nitroprusside or nitroglycerin. In general, segments located more proximally dilated less than those located more distally after either agent. We conclude that both nitroprusside and nitroglycerin are potent dilators of large epicardial and of smaller intramuscular coronary artery segments. The magnitude of dilation of all measured left coronary artery segments appeared remarkably similar with nitroprusside and nitroglycerin given in doses that produced a similar reduction in aortic pressure.
Hepatocyte growth factor (HGF) plays a key role in tissue homeostasis and repair in many organs including lung, heart, kidney, liver, and skin. HGF is a heterodimer comprised of an N−terminal hairpin, four kringle domains, and a serine protease−like domain with a total of 20 intramolecular disulfide bonds. Due to its complex structure, large scale synthesis of full length HGF has not been possible in quantities sufficient for clinical use, despite its potential therapeutic uses. Listeria monocytogenes, an facultative intracellular pathogen, binds to the HGF receptor c−Met via its surface protein internalin B (InlB) as a part of its cellular invasion mechanism. The InlB protein N−terminal domain is comprised of a cap structure, a leucine rich repeat domain (LRR), and an interrepeat region (IR) (total, aa 36−321) that together bind to and partially activate the HGF receptor c−Met. The LRR domain has a stable β−sheet structure, and is easily produced in large quantities using standard E. coli protein synthesis systems. We demonstrate that the extended LRR domain has motogenic and anti−apoptotic activity in primary pulmonary artery endothelial cells (PAEC). This peptide also activates p42/p44 MAPK but not Akt. We have produced a modified extended LRR dimer (2XLRR), that activates both p42/p44 MAPK as well as Akt in PAEC. This added pathway of signal transduction is associated with a gain of cell proliferation in biological function. The modified InlB LRR dimer may be a useful reagent to induce tissue repair. This abstract is funded by: NIH R01 HL073929. Am J Respir Crit Care Med 179;2009:A5365 Internet address: www.atsjournals.org Online Abstracts Issue
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.