In vivo and in vitro modulation of central type benzodiazepine receptors by phosphatidylserine.
Brain Res Mol Brain Res
; 5(1): 9-15, 1989 Jan.
Article
em En
| MEDLINE
| ID: mdl-2538706
The in vivo and in vitro modulation of central benzodiazepine binding sites (BDZ-R) by phosphatidylserine purified from bovine cerebral cortex (BC-PS) was studied. Five days i.p. administration of 15 mg/kg/day of BC-PS liposomes increased the maximal number of binding sites (Bmax) for [3H]flunitrazepam in cerebral cortical membranes. In contrast, the density of hippocampal benzodiazepine recognition binding sites decreased. In cerebellar membranes, BC-PS treatment did not alter the characteristics of [3H]flunitrazepam binding. Similar experiments using phosphatidylcholine extracted from bovine brain (BC-PC) resulted in no changes in the [3H]flunitrazepam binding in the 3 neural structures studied. Confirming previous results, rats submitted to an acute swimming stress showed a decrease in the density of cerebral cortex BDZ-R. Animals treated with BC-PS liposomes before stress showed cortical [3H]flunitrazepam binding significantly below treated, unstressed animals but not below controls. The effects of BC-PS liposomes appeared to be selective for the central type of BDZ-R since no changes were observed in [3H]RO 5-4864 binding, a radioligand specific for the peripheral type BDZ-R. Preincubation of cerebral cortical and cerebellar synaptosomal membranes with BC-PS liposomes (1-300 micrograms per assay) significantly increased in a concentration-dependent manner (up to 100 micrograms) the [3H]flunitrazepam binding. Scatchard analysis revealed changes in the apparent affinity without alterations in the Bmax. Very similar results were obtained using a purified PS from spinal cord. BC-PC, phosphatidylinositol, phosphatidic acid and the lyso derivatives of PS and PC (lysoPS and lysoPC) were found to be ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatidilserinas
/
Encéfalo
/
Receptores de GABA-A
Limite:
Animals
Idioma:
En
Revista:
Brain Res Mol Brain Res
Assunto da revista:
BIOLOGIA MOLECULAR
/
CEREBRO
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda