Lack of cholinergic modulation of tyrosine hydroxylase activation by potassium.
Acta Physiol Pharmacol Latinoam
; 34(3): 235-43, 1984.
Article
em En
| MEDLINE
| ID: mdl-6152371
Cholinergic modulation on the regulation of tyrosine hydroxylase was studied in guinea pig atria depolarized with high potassium concentration. In these conditions there was an increment in tyrosine hydroxylase activity as well as in the release of radioactivity from atria preincubated with 3H-noradrenaline. Both effects were concentration-dependent. Incubation in the presence of 10 microM methacholine, 31 microM 1,1 dimethyl-4-phenylpiperazinium iodide (DMPP), 0.15 microM atropine or 83 microM hexamethonium did not affect tyrosine hydroxylase activation by 100 mM K+. The percentage of activation was reduced however, when 7 microM physostigmine (acetylcholinesterase inhibitor) was present during depolarization. This effect is unlikely to be related to the increase of acetylcholine concentration in the interface, but more probably to a direct effect on the enzyme. In conclusion, tyrosine hydroxylase activation induced by 100 mM potassium appears to be unrelated to the stimulation of nicotinic and muscarinic presynaptic receptors.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Tirosina 3-Mono-Oxigenase
/
Receptores Colinérgicos
Limite:
Animals
Idioma:
En
Revista:
Acta Physiol Pharmacol Latinoam
Assunto da revista:
FARMACOLOGIA
/
FISIOLOGIA
Ano de publicação:
1984
Tipo de documento:
Article
País de publicação:
Argentina