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Transient cerebral ischemia in the rat: a study by nuclear magnetic resonance spectroscopy
No full textThe energy state and the levels of metabolites involved in the phospholipid turnover during and following a transient cerebral ischemia have been evaluated with the aids of 31P and 1H nuclear magnetic resonance spectroscopy. Ischemia was induced by electrocoagulation of vertebral arteries in combination with transient occlusion of both common carotid arteries. After 10-min ischemia, the brain energy charge and the levels of high-energy phosphates were reduced, whereas lactic acid levels had undergone an 8-fold increase. Sixty minutes after cerebral blood flow recovery, brain energy charge and levels of high-energy phosphates returned to basal values, whereas lactic acid levels remained persistingly elevated; an increase in phosphocreatine was also observed. At this same time, glycerolphosphorylcholine levels were found to be significantly reduced
Disinhibition of the hypothalamo pituitary adrenocortical axis as a marker of brain aging in the rat: a model for the study of anti aging agents
No full textMultivariate data analysis in biochemistry: a new integrative approach to metabolic control in brain aging
No full textPrincipal component anal. (PCA) allows one to obtain a quant. measure of the state of metab. as a whole. This method was applied to the study of energy metab. during the aging process and of the effect of a drug (acetyl-1-carnitine) on the aging brain
VALPROIC ACID AND BICUCULLINE AFFECT TREFORMATION OF GLYCEROLIPID IN RAT BRAIN
No full textTo ascertain the effects of bicuculline and of sodium valproate on the incorporation of glycerol into rat brain lipid, rats were divided into 5 groups: (a) controls; (b) treated with sodium valproate
(400 mg/kg body wt); (c) treated with bicuculline (12.5 umol/kg body wt); (d) treated with sodium valproate as in (b) + bicuculline as in (c); and (e) treated with bicuculline (25 umol/jkg body wt). Only rats of group (e) had seizures, which lasted until the end of the experiment. Each animal received 20 uCi of [2-3H]glycerol by intraventricular route and was sacrificed 12 min afterwards. Hippocampi and cerebella were taken and lipid extracted and separated by chromatography. The type of treatment infiuenced very much the fate of injected, labeled glycerol. Indeed, total recovered radioactivity increased following either convulsions or the administration of valproate, whereas both treatments decreased the amount of radioactivity incorporated into lipid. These effects were more evident in cerebella than in hippocampi.
The distribution of radioactivity among lipid classes (diglyceride, triglyceride and total phospholipid) was also affected by seizures, which decreased the labeling ratio phospholipid/neutral lipid. The
distribution of radioactivity among phospholipid classes was infiuenced by bicuculline (both at convulsant . and non-convulsant doses) and these effects were sometimes antagonized by valproate. We conclude that some effects ofbicuculline are exerted through the systemic modifications due to seizures and that other effects are probably connected to neuronal hyperfiring. The data reported in this paper are consistent with both mechanisms of action proposed for valproate, i.e. increased membrane permeability and modifications of GABAergic systems
CEREBELLAR LIPID METABOLISM IS AFFECTED BYBICUCULLINE-INDUCED SEIZURES AND BY SOMEANTICONVULSIVE DRUGS
No full textRats were divided into 5 groups to study the effects of bicuculline-induced convulsions and of some anticonvulsive drugs on the initial stage of glycerol incorporation into cerebellar lipids.
Groups were: (a) controls; (b) treated with sodium valproate (400 mg./kg); (c) treated with bicuculline (25 micromol./kg); (d) treated with diazepam (2 mg/kg); (e) treated with diphenylhydantoin (75 mg./kg). Only rats of group (c) had seizures which lasted until the sacrifice ofthe animals.
Drugs were administered intraperitoneally 25 min before the isotope (20 micro Ci of [2-3H]glycerol, which was injected into brain ventriculi), except bicuculline whose administration was simultaneous to that of labeled glycerol. Rats were sacrificed 12 min after the injection of the radioactive precursor. Cerebella were taken and lipid and water-soluble extracts examined.
The treatment very much influenced the fate oflabeled, injected glycerol. Indeed, the radioactivity recovered in water-soluble extracts increased dramatically during convulsions or following
the administration of any tested drugs, whereas the radioactivity incorporated into lipid decreased.
The distribution of lipid radioactivity between neutral glycerolipid and glycerophospholipid was affected by seizures but not by anticonvulsive drugs. Therefore the performed treatments produced two effects: one was common to all tested drugs, whereas the other could be observed only after bicuculline
Acetyl-L-carnatine reduces the age-dependent loss of glucocorticoid receptors in the rat hippocampus: An autoradiographic study
No full textHippocampus and adrenocortical secretion in the aging rat: morpho functional correlates.
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