Role of mast cell- and non-mast cell -derived inflammatory mediators in immunologic induction of synaptic plasticity
Braz. j. med. biol. res
;
30(7): 909-12, July 1997. tab, graf
Artigo
em Inglês
| LILACS
| ID: lil-197244
RESUMO
We have previously discovered a long-lasting enhancement of synaptic transmission in mammal autonomic ganglia caused by immunological activation of ganglionic mast cells. Subsequent to mast cell activation, lipid and peptide mediators are released which may modulate synpatic function. In this study we determined whether some mast cell-derived mediators, prostaglandin D2 (PGD2; 1.0 muM), platelet aggregating factor (PAF; 0.3 muM) and U44619 (a thromboxane analogue; 1.0 muM), and also endothelin-1 (ET-1; 0.5 muM) induce synaptic potentiation in the guinea pig superior cervical ganglion (SCG), and compared their effects on synaptic transmission with those induced by a sensitizing antigen, ovalbumin (OVA; 10 mug/ml). The experiments were carried out on SCGs isolated from adult male guinea pigs (200-250 g) actively sensitized to OVA, maintained in oxygenated Locke solution at 37 graus Celsius. Synaptic potentiation was measured through alterations of the integral of the post-ganglionic compound action potential (CAP). All agents tested caused long-term (LTP; duration = 30 min) or short-term (STP; <30 min) potentiation of synaptic efficacy, as measured by the increase in the integral of the post-ganglionic CAP. The magnitude of mediator-induced potentiation was never the same as the antigen-induced long-term potentiation (A-LTP). The agent that best mimicked the antigen was PGD2, which induced a 75 per cent increase in CAP integral for LTP (antigen 94 per cent) and a 34 per cent increase for STP (antigen 91 per cent). PAF-, U44619-, and ET-1 induced increases in CAP integral ranged for LTP from 34 to 47 per cent, and for STP from 0 to 26 per cent. These results suggest that the agents investigated may participate in the induction of A-LTP.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Mediadores da Inflamação
/
Plasticidade Neuronal
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
1997
Tipo de documento:
Artigo
/
Congresso e conferência
/
Documento de projeto
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