Evidence that pharmacological manipulations of central L-arginine-NO pathway influence blood pressure and heart rate in rats.
In the present study we have investigated whether pharmacological manipulations of central L-arginine-nitric oxide (L-Arg-NO) pathway could affect blood pressure (BP) and heart rate (HR) in normotensive rats either untreated or pretreated with E. coli lipopolysaccharide (LPS). The intracerebroventricular injection (i.c.v.) of N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthesis, caused a fall of BP and HR in LPS-treated but not in control rats. Furthermore, the pressor responses to i.c.v. injection of N-methyl-D-aspartate (NMDA) were enhanced by L-Arg or LPS treatment and, in both cases, this potentiation was blocked by L-NAME. The present results show that in some experimental conditions, such as activation of NMDA receptors or LPS pretreatment, the central microinfusion of drugs affecting the L-Arg-NO pathway may interfere with BP and HR.
Mollace
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Department of Biology, University of Rome Tor Vergata, Italy.
De Francesco
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Nisticó
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D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D001794:Blood Pressure / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004731:Endotoxins / Q000494:pharmacology; D006339:Heart Rate / Q000502:physiology*; D007276:Injections, Intraventricular; D008070:Lipopolysaccharides; D008297:Male; D016202:N-Methylaspartate / Q000008:administration & dosage / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology
D004731:Endotoxins; D008070:Lipopolysaccharides; D016194:Receptors, N-Methyl-D-Aspartate; D009569:Nitric Oxide; D016202:N-Methylaspartate; C044101:endotoxin, Escherichia coli; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D019331:NG-Nitroarginine Methyl Ester