Methylarginines in Mice with Experimental Atherosclerosis

We studied the dynamics of indexes for the system of endogenous regulation of NO bioavailability. The content of NO synthase inhibitors (monomethylarginine and asymmetric dimethylarginine) in the blood of mice was measured after intraperitoneal injections of a nonionic surfactant poloxamer 407 for 2 and 14 weeks. The concentrations of both methylarginines in animals with atherosclerosis due to 14-week administration of poloxamer were much higher than in control specimens. The amount of arginine and symmetric dimethylarginine practically did not differ from the control. Poloxamer-induced model of atherosclerosis is characterized by increased content of NO synthase inhibitors. These changes contribute to the development of endothelial dysfunction and atherosclerosis.