Differential effects of nitric oxide synthase inhibitors in rats
The Korean Journal of Physiology and Pharmacology
; : 99-104, 2000.
Article
in En
| WPRIM
| ID: wpr-728333
Responsible library:
WPRO
ABSTRACT
We investigated the action of NOS inhibitors on NOS in rats. Both of nitric oxide synthase inhibitors, NG-monomethyl-L-arginine (L-NMMA, 3 micrometer) or NG-nitro-L-arginine methylester (L-NAME, 30 micrometer), augmented phenylephrine (PE, 10-7 M)-induced contraction which was inhibited by acetylcholine (ACh) in rat thoracic aorta. This augmentation by L-NAME or L-NMMA was attenuated with the treatment of NO precursor, arginine. ACh, however, decreased the augmentation induced by L-NMMA, but not by L-NAME. Superoxide dismutase (SOD, 50 u/ml) potentiated an inhibitory effect of ACh on the PE (10-7 M)-induced contraction. It has been known that platelet activating factor itself induces iNOS. Platelet activating factor (PAF, 10-7 M) inhibited PE (10-7 M)-induced contraction. Pretreatment with L-NMMA (30 mM) or L-NAME (30 mM) significantly blocked the inhibitory action of PAF on PE-induced contraction. L-NMMA (100 mM) or L-NAME (100 mM) reduced nerve conduction velocity (NCV) relevant to nNOS in rat sciatic nerve. ACh attenuated the reduction of NCV by L-NMMA-, but not by L-NAME-induced reduction of NCV. These results suggest that L-NMMA and/or L-NAME have different action on three types of NOS in rats.
Full text:
1
Index:
WPRIM
Main subject:
Aorta, Thoracic
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Phenylephrine
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Arginine
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Sciatic Nerve
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Superoxide Dismutase
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Platelet Activating Factor
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Acetylcholine
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Nitric Oxide Synthase
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NG-Nitroarginine Methyl Ester
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Nitroarginine
Limits:
Animals
Language:
En
Journal:
The Korean Journal of Physiology and Pharmacology
Year:
2000
Type:
Article