Effect of nitric oxide synthase inhibition on the acetylcholine response in the perfused hind limb of rats.
The effect of nitric oxide (NO) synthase inhibition on acetylcholine-induced vasodilation in the perfused rat hind limb was investigated to find the contribution of NO to such relaxation. Although NO synthase inhibition with 150 micrograms L-nitro-arginine increased vascular resistance considerably, from 7.28 +/- 0.29 to 10.83 +/- 0.44 mm Hg.min/ml (n = 7), the acetylcholine responses were not attenuated. Acetylcholine (10 micrograms) induced a peak relaxation of 66 +/- 4% before, and 63 +/- 7% after L-nitro-arginine. The duration of the peak and total responses, examined in separate sets of animals (n = 12), was similar in both circumstances (61 +/- 4 s before vs. 53 +/- 5 s after, and 7.45 +/- 0.61 min before vs. 7.48 +/- 0.64 min after respectively). These results suggest that a non-NO factor is responsible for acetylcholine-stimulated relaxation in the rat hind limb vascular bed.
Brouwers-Ceiler
D L
DL
Department of Pharmacology, University of Limburg, Maastricht, Netherlands.
Nelissen-Vrancken
H J
HJ
Smits
J F
JF
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006614:Hindlimb / Q000098:blood supply* / Q000187:drug effects; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D019335:Nitroarginine / Q000494:pharmacology; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical; D014665:Vasodilator Agents / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D019335:Nitroarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000109:Acetylcholine