Regulation of blood pressure by L-arginine-nitric oxide pathway within the superior colliculus of rats.
Injection into the superior colliculus of anaesthetised rats of the nitric oxide (NO) synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME; 1 micromol), but not its inactive enantiomer N(omega)-nitro-D-arginine methyl ester (D-NAME; 1 micromol), significantly (P < 0.01) increased the mean arterial blood pressure. Injection to the superior colliculus of L-arginine (L-Arg; 1 micromol), the substrate for NO synthase, significantly (P < 0.01) lessened the pressor effect of L-NAME, while D-arginine (D-Arg; 1 micromol) did not affect it. L-Arg (7.5 micromol), but not D-Arg (7.5 micromol) administered at the peak of the pressor response to L-NAME (1 micromol) also partially reversed this pressor response (P < 0.05). These data would suggest that endogenously produced NO acts within the superior colliculus to modulate the arterial blood pressure.
D'Amico
M
M
Institute of Pharmacology and Toxicology, 2nd University of Naples, Italy.
Rossi
F
F
Warner
T D
TD
D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000633:toxicity*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000633:toxicity*; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism; D013477:Superior Colliculi / Q000187:drug effects* / Q000502:physiology
D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester