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The time-course of DNA fragmentation in the choroid plexus and the CA1 region following transient global ischemia in the rat brain. The effect of intra-ischemic hypothermia

The time-course of DNA fragmentation in the CA1 region of the hippocampus and the choroid plexus was studied following induction of transient forebrain ischemia under lethal normothermic (37°C), or sublethal hypothermic (33°C) conditions. Oligonucleosomal- and high-molecular-weight DNA fragmentation were analysed by conventional agarose gel electrophoresis and pulsed-field gel electrophoresis, res

A simple in vitro model of ischemia based on hippocampal slice cultures and propidium iodide fluorescence

This protocol describes a model of cerebral ischemia based on organotypic hippocampal slice cultures and quantitative assessment of cell death by use of propidium iodide and image analysis. The cultures were made from rat hippocampal slices that were obtained at postnatal day 4-7 and allowed to develop for > 14 days in vitro. For induction of 'in vitro ischemia', the cultures were washed in glucos

Mitochondrial permeability transition induced DNA-fragmentation in the rat hippocampus following hypoglycemia

In the present study the time-course of DNA fragmentation following insulin-induced hypoglycemia was examined. In situ localization of DNA breaks were studied by the terminal deoxynucleotidyl transferase-mediated biotin- deoxyuridine triphosphate nick-end labelling method, and the temporal profile of DNA-fragmentation by agarose gel electrophoresis. Cell nuclei displayed terminal deoxynucleotidyl

Influence of MK-801 on brain extracellular calcium and potassium activities in severe hypoglycemia

The purpose of the present study was to examine the effect of blockade of N-methyl-D-aspartate (NMDA) receptors on the depolarization associated with severe hypoglycemia, which is commonly preceded by one or a few transient depolarizations reminiscent of cortical spreading depression (CSD). In the cerebral cortices of rats [K+](e) and [Ca2+](e) were measured with ion-selective microelectrodes. NMD

Cerebral platelet thromboembolism and thromboxane synthetase inhibition

Platelet aggregating sodium arachidonate was slowly infused into the internal carotid artery (1 mg, 100 µl, 1µl/s) of nitrous oxide anesthetized rats. The electroencephalographic activity recorded by a Cerebral Function Monitor from the injected hemisphere was reduced within minutes. The so matose nsory evoked responses to contralateral electrical stimulation of the whisker area were eliminated on

Ischemic brain damage in rats following cardiac arrest using a long-term recovery model

A model is described in which transient complete cerebral ischemia is induced in rats by intracardiac injection of potassium chloride. The animals were intubated and mechanically ventilated with a nitrous oxide/oxygen (70:30) mixture. Cardiac arrest was achieved following a brief period of ventricular fibrillation. After 5-6 min, the circulation was restored by cardiopulmonary resuscitation and pa

Ischemic brain injury : The importance of calcium, lipolytic activities, and free fatty acids

Ischemic brain insults are accompanied by several metabolic alterations. In the present review, the adverse reactions, which might be important for the outcome of these insults, are those related to phospholipid and polyunsaturated fatty acid metabolism triggered by the disturbed calcium ion homeostasis in combination with energy depletion following ischemia. These conditions lead to an activation

Amelioration of ischaemic brain damage by postischaemic treatment with flunarizine

The effect of flunarizine, a calcium entry blocker, on ischaemic damage was investigated using a new model of forebrain ischaemia. Fasted rats were subjected to nine minutes ischaemia and one week recovery. One group served as control; a second was pretreated orally with flunarizine; a third group received postischaemic flunarizine treatment Focussing on the hippocampus, an area of high susceptibi

Influence of acidosis on lipid peroxidation in brain tissues in vitro

To study the influence of acidosis on free radical formation and lipid peroxidation in brain tissues, homogenates fortified with ferrous ions and, in some experiments, with ascorbic acid were equilibrated with 5–15% O2 at pH values of 7.0, 6.5, 6.0, and 5.0, with subsequent measurements of thiobarbituric acid-reactive (TBAR) material, as well as of water- and lipid-soluble antioxidants (glutathion

Evidence for amelioration of ischaemic neuronal damage in the hippocampal formation by lesions of the perforant path

The effect of lesions of two excitatory afferent pathways on the cellular damage in the hippocampus following complete cerebral ischaemia was investigated in the rat Lesions transecting the perforant path led to a significant decrease in cellular damage in the hippocampal CA1 region ipsilateral to the lesion as compared to the contatterai side and to control. Lesions of the fimbria-fornix, on the

Cyclic AMP Concentrations in Rat Neocortex and Hippocampus During and Following Incomplete Ischemia : Effects of Central Noradrenergic Neurons, Prostaglandins, and Adenosine

Abstract: The concentrations of cyclic AMP, noradrenaline, glycogen, glucose, lactate, pyruvate, labile phosphate compounds, and free fatty acids were investigated in the rat neocortex and hippocampus during and following cerebral ischemia. An incomplete ischemia of 5 and 15 min duration was induced by bilateral carotid clamping combined with hypotension. The postischemic events were studied after

The dentate gyrus in hypoglycemia : Pathology implicating excititoxin-mediated neuronal necrosis

A detailed light- and electron-microscopic study of the damage to the rat dentate gyrus in hypoglycemia was undertaken, in view of the previously advanced hypothesis that hypoglycemic nerve cell injury is mediated by a released neurotoxin. The distribution of neuronal necrosis showed a relationship to the subarachnoid cisterns. Electron microscopy of the dentate granule cells and their apical dend

Trypsin activation of porcine procolipase. Kinetics of activation and effects on lipid binding

The kinetics of trypsin activation of pancreatic procolipase was investigated and the pH dependence of the binding of procolipase and colipase to a tributyrine-bile salt interface studied. The Km was 0.06 mM and Kcat 8 s-1, and was of the same order of magnitude as for the activation of pancreatic zymogens. At basic pH values colipase had a higher affinity for the tributyrine-bile salt interface a

Cerebral metabolic and circulatory effects of 1,1,1-trichloroethane, a neurotoxic industrial solvent - 1. Effects on local cerebral glucose consumption and blood flow during acute exposure

The effects of inhaled 1,1,1-trichloroethane (3500, 6000, and 7800 ppm) on behavior, local cerebral blood flow, and local cerebral glucose consumption were studied in awake rats. The effect of the solvent inhalation on the EEG pattern and local cerebral blood flow was also studied in paralyzed animals under N2O analgesia. Exposure of awake animals to 6000 ppm 1,1,1-trichloroethane induced a decrea

Influence of Severe Hypoglycemia on Brain Extracellular Calcium and Potassium Activities, Energy, and Phospholipid Metabolism

Abstract: In the cerebral cortices of rats, during insulininduced hypoglycemia, changes in the concentrations of labile phosphate compounds [ATP, ADP, AMP, and phosphocreatine (PCr)] and glycolytic metabolites (lactate, pyruvate, and glucose) as well as phospholipids and free fatty acids (FFAs) were studied in relation to extracellular potassium and calcium activities. Changes in extracellular cal