Inhibition of carbonic anhydrase by nitric oxide
Puscas, I.; Coltau, M.
Arzneimittel-Forschung 45(8): 846-848
1995
ISSN/ISBN: 0004-4172 PMID: 7575744 Document Number: 449352
The aim of the present study was to follow the effect of nitric oxide (NO) on carbonic anhydrase in vitro and in vivo. The effect of L-arginine (as source of NO), as well as that of its analogue, nitro-G-monomethyl-L-arginine, an inhibitor of NO synthesis on carbonic anhydrase, were also studied. In vitro results showed that L-arginine activates carbonic anhydrase, while N-G-monomethyl-L-arginine does not modify its activity. In vivo, L-arginine and N-G-monomethyl-L-arginine increased carbonic anhydrase activity by 72% and, 160% respectively. Administration of L-arginine, as a source of NO, and of acetazolamide before administration of N-G-monomethyl-L-arginine abolished the activating effect of the analogue on carbonic anhydrase. These results lead to the conclusion that inhibition of NO synthesis by N-G-monomethyl-L-arginine induces increase of carbonic anhydrase activity. The data also suggest that NO biosynthetized from L-arginine inhibits carbonic anhydrase.