Lead inhibits Ca(2+)-stimulated nitric oxide synthase activity from rat cerebellum.
Neurosci Lett
; 196(1-2): 65-8, 1995 Aug 18.
Article
en En
| MEDLINE
| ID: mdl-7501259
ABSTRACT
Pb2+ is reported to cause cognitive dysfunctions in children and to inhibit long-term potentiation (LTP), a model form of synaptic plasticity that involves nitric oxide (NO). Since Pb2+ interacts with Ca(2+)-calmodulin, and brain nitric oxide synthase (NOS) is Ca(2+)-calmodulin regulated, we examined the effects of Pb2+ on NOS activity prepared from rat cerebellum. NOS required NADPH and was inhibited by monomethylarginine. Full NOS activity required 0.6 microM free Ca2+ and was inhibited 50% by 17 nM and 100% by 80 nM free Pb2+. NOS inhibition by Pb2+ was reversible by increasing free Ca2+ concentrations. Evaluation of other divalent cations resulted in the following ranked order of potencies Cu2+ > Pb2+ >> Zn2+; Fe2+, Ba2+, Mg2+, Mn2+, and Sr2+ were ineffective. These results suggest that Pb2+ inhibition of brain NOS activity may account for some of the effects of Pb2+ on the CNS.
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Banco de datos:
MEDLINE
Asunto principal:
Cerebelo
/
Calcio
/
Óxido Nítrico Sintasa
/
Plomo
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Año:
1995
Tipo del documento:
Article