Open AccessBarium Activates Rat Cerebellar Nitric Oxide Synthase
Author(s) -
Jun Yamazaki,
Tetsuro Urushidani,
Taku Nagao
Publication year - 1996
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - Uncategorized
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.70.351
Subject(s) - chemistry , calmodulin , nitric oxide , nitric oxide synthase , citrulline , cerebellum , arginine , barium , vanadate , biophysics , biochemistry , stereochemistry , inorganic chemistry , endocrinology , biology , enzyme , amino acid , organic chemistry
Ba2+ is known to pass through N-methyl-D-aspartate receptor channels and cause an increase in cGMP levels in rat cerebella. In the present study, we compared the activation of rat cerebellar nitric oxide synthase (NOS) by Ba2+ with that produced by Ca2+. Both cations stimulated L-citrulline formation in the presence of calmodulin in identical fractions eluted from an anion exchange column with a salt gradient. EC50 values for Ca2+ and Ba2+ were 200 nM and 50 microM, respectively. The IC50 of NG-monomethyl-L-arginine was the same (200 nM). These indicate a possible action of Ba2+ on NOS through the calmodulin-dependent pathway.