Nitric oxide synthesized from L‐arginine regulates vascular tone in the coronary circulation of the rabbit
JL Amezcua, RMJ Palmer… - British journal of …, 1989 - Wiley Online Library
JL Amezcua, RMJ Palmer, BM De Souza, S Moncada
British journal of pharmacology, 1989•Wiley Online Library1 The role of nitric oxide (NO) in the regulation of the vascular tone of the coronary
circulation of the Langendorff‐perfused rabbit heart was investigated. 2 NG‐monomethyl‐L‐
arginine (L‐NMMA; 10–100 μm), a specific inhibitor of NO formation from L‐arginine (L‐Arg),
but not its D‐enantiomer (D‐NMMA; 100 μm) produced a dose‐related, sustained increase
in the coronary perfusion pressure (CPP). In addition, L‐NMMA inhibited the vasodilator
responses of acetylcholine (ACh), unmasking in some instances its direct vasoconstrictor …
circulation of the Langendorff‐perfused rabbit heart was investigated. 2 NG‐monomethyl‐L‐
arginine (L‐NMMA; 10–100 μm), a specific inhibitor of NO formation from L‐arginine (L‐Arg),
but not its D‐enantiomer (D‐NMMA; 100 μm) produced a dose‐related, sustained increase
in the coronary perfusion pressure (CPP). In addition, L‐NMMA inhibited the vasodilator
responses of acetylcholine (ACh), unmasking in some instances its direct vasoconstrictor …
- 1The role of nitric oxide (NO) in the regulation of the vascular tone of the coronary circulation of the Langendorff‐perfused rabbit heart was investigated.
- 2NG‐monomethyl‐L‐arginine (L‐NMMA; 10–100 μm), a specific inhibitor of NO formation from L‐arginine (L‐Arg), but not its D‐enantiomer (D‐NMMA; 100 μm) produced a dose‐related, sustained increase in the coronary perfusion pressure (CPP). In addition, L‐NMMA inhibited the vasodilator responses of acetylcholine (ACh), unmasking in some instances its direct vasoconstrictor effect. These effects of L‐NMMA were attenuated by L‐Arg.
- 3L‐NMMA (10 and 30 μm), but not D‐NMMA (30 μm), caused a long‐lasting inhibition of NO formation which was reversed by L‐Arg (30 and 100 μm), but not by D‐Arg (100 μm).
- 4This study indicates that the formation of NO from L‐Arg in the coronary circulation of the rabbit plays a role both as a regulator of vascular tone and as a mediator of the vasodilatation induced by ACh.
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