2013). In contrast, some studies reported that intra-arterial (intracarotid) and intravenous (jugular) administration of 14C-NAC resulted in good BBB permeability (McLellan et al. 1995). BBB crossing by 14C-NAC increased following intraperitoneal administration of lipopolysaccharide (LPS). Interestingly, NAC-amide (NACA is an active derivation of NAC) has been measured

in brain after oral or interperitoneal administration, but not NAC itself (Samuni et al. 2013). When NAC was replaced with Inhibitors,research,lifescience,medical NAC ethyl ester, a dramatic increase in the brain levels of NAC and cysteine was detected probably due to a rapid hydrolysis of NAC ethyl ester (Samuni et al. Inhibitors,research,lifescience,medical 2013). Effect of NAC on the functions of vascular smooth muscle cells Excessive proliferation of vascular smooth muscle cells (VSMCs) contributes to atherosclerosis, a major cause of cerebrovascular disease. NAC partially inhibits ox-low-density lipoprotein (ox-LDL, a pro-oxidant) and urotensin-(a potent vasoconstrictor) stimulated proliferation of VSMCs. These effects of NAC raise the possibility of a therapeutic benefit to prevent stroke or atherosclerosis progression in patients with hypertension and hypercholesterolemia (N-acetylcysteine 2000). Additionally, NAC inhibited serum PDGF- and thrombin-stimulated

extracellular single-regulated kinase (ERK2), c-JUN N-terminal kinase (JNK1), Inhibitors,research,lifescience,medical and p38 mitogen-activated protein kinase (MAPK) activation as well as expression of the c-Fos (70%), c-Jun (50%) and JunB (70%) genes, suggesting redox-sensitive mechanisms for protective effects of NAC in patients with major vascular risk factors (Su Inhibitors,research,lifescience,medical et al. 2001).

Furthermore, NAC almost completely inhabits the Ag II-induced downregulation of AT (Dekhuijzen 2004)-R mRNA (Angiotensin II receptor, type 1) (Ichiki et al. 2001). NAC also blocks serotonin-stimulated superoxide production and ERK-MAPK Inhibitors,research,lifescience,medical phosphorylation in VSMCs (Lee et al. 1999). As a result of these multiple mechanisms of action, NAC reduced thickening of the neointima by 39% in rabbit aorta after injury produced by balloon (Ghigliotti et al. 2001). Finally, NAC inhibits cyclooxygenase-2 induction by benzopyrene, an atherogenic component of cigarette smoking (Yan et al. 2000). Role of NAC in 5-FU nmr atherosclerotic plaque stability ROS such as superoxide, nitric oxide (NO), these and H2O2 can modulate the activities of matrix-degrading proteases, matrix metalloproteinases (MMPs) and contribute to the instability of a vulnerable atherosclerotic plaque (Xu et al. 1999). Ox-LDL activates AP-1 and NF-kB transcription factors, promotes macrophage-mediated matrix disruption in the rupture-prone atherosclerotic plaques (Xu et al. 1999). NAC inhibits the homocysteine-enhanced expression of an ox-LDL receptor, lox-1 in the endothelium (Nagase et al. 2001).