NG-monomethyl-L-arginine does not inhibit the hindquarters vasodilator action of endothelin-1 in conscious rats.
Regional haemodynamic responses to endothelin-1 were assessed in conscious, unrestrained Long Evans rats, chronically instrumented with pulsed Doppler flow probes. Bolus injection of endothelin-1 (0.04 nmol) caused an early transient hypotension and increase in hindquarters vascular conductance. In the presence of NG-monomethyl-L-arginine (L-NMMA), which inhibits endothelial cell nitric oxide production, the hindquarters vasodilator response to endothelin-1 was unchanged and similar to that seen in the presence of vasopressin when the latter was infused to simulate the pressor effects of L-NMMA. These results indicate that the hindquarters vasodilatation in response to endothelin-1 is not dependent upon release of nitric oxide from endothelial cells.
Gardiner
S M
SM
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, U.K.
Compton
A M
AM
Bennett
T
T
Palmer
R M
RM
Moncada
S
S
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D016232:Endothelins; D006339:Heart Rate / Q000187:drug effects; D006614:Hindlimb / Q000098:blood supply*; D008297:Male; D009569:Nitric Oxide / Q000494:pharmacology; D010455:Peptides / Q000037:antagonists & inhibitors*; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects; D019323:omega-N-Methylarginine
D016232:Endothelins; D010455:Peptides; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine