1,721,045 research outputs found
Toffano G., Savoini G., Aporti F., Calzolari S.,Consolazione A., Maura The functional recovery of damaged brain: the effect of GM1 monosialoganglioside
No full textDopamine Modulation of Different Intracellular Changes induced by Prolactin Releasing agents
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Serine phospholipids as endocoids.
No full textUnusual phospholipid effects may occur when their distribution in the membrane is altered or when uncontrolled metabolic reactions yield elevated concentrations of their short lived derivatives. Serine phospholipids are normally buried in the internal side of plasma membrane. Upon exposure to the extracellular environment they elicit a response from selected cell populations. The interaction between these phospholipids and neuroactive compounds in rat peritoneal mast cells may indicate that serine phospholipids have a role in the nervous system during development
Aging reduces the GABA-dependent 36Cl- flux in rat brain membrane vesicles.
No full textThe function of the chloride channel associated to GABAA receptor complex was analyzed in the brain of aged rats by measuring the chloride flux across the neuronal membrane and its modulation by drugs acting at the level of the GABA receptor complex and 35S-TBPS binding. The basal 36Cl- uptake by brain membrane vesicles of aged rats was higher (22%) than that observed in those of adult rats. The higher 36Cl- uptake found in cortical membrane vesicles of senescent rats was not sensitive to the action of bicuculline indicating that it was not the consequence of a tonic GABAergic modulation. Moreover, the stimulation of 36Cl- uptake induced by GABA was markedly lower in membrane vesicles of aged rats than that observed in those of adult rats. Accordingly, the stimulation of 36Cl- efflux elicited by GABA (18%) and pentobarbital (26%) was higher in membrane vesicles of adult rats with respect to that (8 and 16%, respectively) of old rats. Finally, a significant decrease of 35S-TBPS binding was observed in membrane preparation from the cerebral cortex, cerebellum and hippocampus of aged-rats. Scatchard plot analysis indicated that the decrease was entirely due to a reduction in the total number of binding sites with no change in their affinity. All together the results indicate that in the rat brain the function of the chloride channel coupled to the GABA/benzodiazepine/barbiturate receptor complex is reduced by aging
Lack of counteracting effect of liposomes on benserazide-induced hyperprolactinemia
No full textBenserazide induces an increase of serum prolactin in man, possibly as
the result of an impairment of the dopamine effect on the pituitary
and/or on the outer median eminence caused by the inhibition on L-dopa
decarboxylase. On the other hand, liposomes obtained from bovine brain
cortex phospholipids reduced serum prolactin possibly through an effect
of phosphatidylserine on dopamine biosynthesis at the level of tyrosine
hydroxylase. Benserazide, given orally (125 mg) to 5 normal subjects,
induced an increase of serum prolactin that did not change when 300 mg
of phospholipid liposomes were given intravenously 60 min later. An
increase of L-dopa synthesis does not seen to be capable to overcome the
effects of the decarboxylase inhibition
EFFECTS OF PHOSPHATIDYLSERINE ADMINISTRATION ON AGE-RELATED STRUCTURAL-CHANGES IN THE RAT HIPPOCAMPUS AND SEPTAL COMPLEX
No full textDendritic spine density of CA1 pyramidal neurons in the hippocampus and morphometric characteristics of the cholinergic neuronal population of the septal complex, were evaluated in young (four months), aged (27 months), and age-matched rats which had received long-term phosphatidylserine (BC-PS) administration (50 mg/kg/die, suspended in the drinking water). In aged rats, spine density decreased significantly by 12.11% in the basal dendrites and by 10.64% in the apical ones, as compared with young controls. In the cholinergic neuronal population of medial septum and diagonal band, aging induced a statistically significant reduction in cell number (-19.6%), in soma area (-18.5%), in cell maximal diameter (-9.2%), and in the area covered by all cholinergic profiles (-33%). By contrast, no significant reductions in the above-mentioned structural parameters were observed in aged BC-PS-treated rats when compared with young animals. The mechanisms underlying the beneficial effects of BC-PS can possibly be ascribed to the pharmacological actions exerted by BC-PS on neuronal membranes, neurotransmission, and/or interaction with NGF
Inhibition of protein kinase activity by apomorphine.
No full textThe effect of apomorphine (1-20 microM) on protein kinase activity was studied in extracts from rat peritoneal mast cells and brain tissue. Apomorphine inhibited the cyclic AMP-dependent and the calcium-plus phosphatidylserine-dependent protein kinase activity with an IC50 between 1 and 6 microM, depending on the tissue and on the protein kinase involved. This effect might explain previous results on the apomorphine-induced inhibition of histamine release in rat peritoneal mast cells
DENDRITIC SPINE DENSITY OF CA1 PYRAMIDAL CELLS IN THE HIPPOCAMPUS OF AGED RATS - EFFECTS OF PHOSPHATIDYLSERINE ADMINISTRATION
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