Mastoparan elicits prostaglandin E2 generation and inhibits inositol phosphate accumulation via different mechanisms in rabbit astrocytes.
Biochim Biophys Acta
; 1310(1): 60-6, 1996 Jan 10.
Article
en En
| MEDLINE
| ID: mdl-9244176
ABSTRACT
The effects of mastoparan on phosphoinositide hydrolysis and prostaglandin E2 (PGE2) generation were investigated in astrocytes cultured from rabbit brain. Mastoparan inhibited the accumulations of [3H]inositol phosphates induced by bradykinin (1 microM) in a time- and concentration-dependent manner. Mastoparan (3-30 microM) also released PGE2 in a time- and concentration-dependent manner. Mastoparan-induced release of PGE2 was inhibited by indomethacin, a cyclooxygenase inhibitor, by dexamethasone, a steroidal anti-inflammatory drug, and by pertussis toxin, an inactivator of some G proteins, such as Gi and Go. Mastoparan also caused [3H]arachidonic acid liberation, which was inhibited by dexamethasone or pertussis toxin. In contrast, indomethacin, dexamethasone and pertussis toxin failed to attenuate mastoparan-induced inhibition of [3H]inositol phosphate accumulation induced by bradykinin. Thus, mastoparan-induced inhibition of phosphoinositide hydrolysis does not involve pertussis toxin-sensitive G protein nor arachidonic acid metabolites. In addition to the inhibition of phospholipase C, mastoparan activates phospholipase A2 through pertussis toxin-sensitive G protein.
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Banco de datos:
MEDLINE
Asunto principal:
Venenos de Avispas
/
Dinoprostona
/
Astrocitos
/
Fosfatos de Inositol
Límite:
Animals
Idioma:
En
Año:
1996
Tipo del documento:
Article