Detection of particulate guanylate cyclase in rat neurohypophysis after stimulation with ANF and BNP: an ultracytochemical study.
Brain Res
; 644(1): 52-8, 1994 Apr 25.
Article
em En
| MEDLINE
| ID: mdl-7913401
ABSTRACT
We investigated the ultracytochemical localization of particulate guanylate cyclase (GC) in the rat neurohypophysis after activation with rat atrial natriuretic factor (rANF) or porcine brain natriuretic peptide (pBNP). Under our experimental conditions, the presence of GC reaction product indicated that rANF and pBNP were strong activators of particulate GC since samples incubated in basal conditions without rANF or pBNP did not reveal any GC reaction product. The rANF-stimulated GC was localized both to pituicytes and to nerve fibers and endings whereas the pBNP-stimulated GC was present exclusively in nerve fibers and endings. Recently, two subtypes of receptors for natriuretic peptides have been identified as two isoforms of particulate GC [24,50]. Our data indicate that the receptors of the two hormones have a partially distinct distribution in the rat neurohypophysis. In pituicytes, GC reaction product was found on plasma membrane of finger-like processes and on the membranes surrounding the lipid droplets. In nerve fibers and endings, GC reaction product was associated with intracellular membranes. This finding suggests that the enzyme could mediate an internal inhibitory action of these hormones on the release of vasopressin and oxytocin.
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Base de dados:
MEDLINE
Assunto principal:
Neuro-Hipófise
/
Fator Natriurético Atrial
/
Guanilato Ciclase
/
Proteínas do Tecido Nervoso
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
1994
Tipo de documento:
Article