BO K Siesjö

Recirculation following 2 h of focal ischemia due to transient middle cerebral artery (MCA) occlusion has previously been found to be accompanied by an initial, partial recovery of the cellular bioenergetic state and of mitochondrial respiratory functions, with secondary deterioration during the first 2-4 h of reflow. Both the free radical spin trap alpha-phenyl-N-tert-butyl nitrone (PBN) and the immunosuppressant drug FK506 ameliorate the damage incurred by the 2-h period of focal ...

Kaasik, A. E., L. Nilsson and B. K. Siesjö. The effect of asphyxia upon the lactate, pyruvate and bicarbonate concentrations of brain tissue and cisternal CSF, and upon the tissue concentrations of phosphocreatine and adenine nucleotides in anesthetized rats. Acta physiol. scand. 1970. 78. 433–447. The effect of asphyxia upon the lactate, pyruvate and bicarbonate concentrations of brain tissue and cisternal CSF, and upon the tissue concentrations of phosphocreatine, ATP, ADP and AMP was ...

Kaasik, A. E., L. Nilsson and B. K. Siesjö. The effect of arterial hypotension upon the lactate, pyruvate and bicarbonate concentrations of brain tissue and cisternal CSF, and upon the tissue concentrations of phosphocreatine and adenine nucleotides in anesthetized rats. Acta physiol. scand. 1970. 78. 448–458. The effect of stagnant hypoxia upon the lactate, pyruvate and bicarbonate concentrations of brain tissue and cisternal CSF, and upon the tissue concentrations of phosphocreatine, ...

The present experiments were undertaken to explore the mechanisms of secondary brain damage in focal ischemia of long duration (2 h), followed by recirculation. Recirculation has previously been found to cause partial recovery and secondary deterioration of cellular bioenergetic state, the subsequent damage being ameliorated by a free radical spin trap, alpha-phenyl-N-tert-butyl nitrone (PBN), even when the drug was given 1 (or 3) h after the start of recirculation. Our objective was to ...

The lactate and pyruvate concentrations in cisternal cerebrospinal fluid (CSF), and the lactate, pyruvate, ATP, ADP, phosphocreatine, and creatine concentrations in brain tissue were measured in cats during hyper- and hypocapnia. (PaCO2 10–100 mm Hg). Both the CSF and the tissue concentrations of lactate and pyruvate varied inversely with the arterial CO2 tension. In hypercapnia the tissue lactate/pyruvate ratio increased in accordance with a theoretical curve, calculated for a pH ...

The objective of the present experiments was to study metabolic correlates to the localization of neuronal lesions during sustained seizures. To that end, status epilepticus was induced by i.v. administration of bicuculline in immobilized and artificially ventilated rats, since this model is known to cause neuronal cell damage in cerebral cortex and hippocampus but not in the cerebellum. After 20 or 120 min of continuous seizure activity, brain tissue was frozen in situ through the skull ...

Levels of mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and the tyrosine kinase receptors trkB and trkC have been studied using in situ hybridization in the rat brain after topical application of KCl to the cortical surface (which induces spreading depression). Repeated episodes of spreading depression during 2 h caused a rapid and marked increase of BDNF mRNA levels in deep and, in particular, superficial cortical layers of the ...

Release of cytochrome c (cyt c) into cytoplasm initiates caspase-mediated apoptosis, whereas activation of Akt kinase by phosphorylation at serine-473 prevents apoptosis in several cell systems. To investigate cell death and cell survival pathways, the authors studied release of cyt c, activation of caspase, and changes in Akt phosphorylation in rat brains subjected to 15 minutes of ischemia followed by varying periods of reperfusion. The authors found by electron microscopic study that ...

In situ hybridization was used to study expression of mRNAs for members of the nerve growth factor (NGF) family in the rat brain after 2 and 10 min of forebrain ischemia and 1 and 30 min of insulin-induced hypoglycemic coma. Two hours after the ischemic insults, the level of brain-derived neurotrophic factor (BDNF) mRNA was markedly increased in the granule cells of the dentate gyrus, and at 24 h it was still significantly elevated. NGF mRNA showed a pronounced increase 4 h after 2 min ...

The objective of the study was to estimate changes in extracellular pH (pHe) and intracellular pH (pHi) during seizures and in the recovery period following the arrest of seizure activity. Seizures of 5- and 20-min duration were induced in rats by fluorothyl added to the insufflated gas mixture, and recovery for 5, 15, and 45 min was instituted by withdrawal of the fluorothyl supply following 20 min of continuous seizures. Changes in pHe were measured by double-barreled, liquid ...

In order to evaluate the metabolism of citric acid cycle intermediates and amino acids in cerebral ischemia, brain tissue was sampled after occlusion of the cerebral circulation for 5 min and, in separate animals, after 15 min of recirculation, with subsequent analyses of cerebral cortex concentrations of citrate, α-ketoglutarate, succinate, fumarate, malate, glutamate, aspartate, GABA, alanine, glutamine, asparagine and ammonia.At the end of the ischemia the tissue was depleted of ...

The present study examines the effects of mild hypothermia and hyperthermia on the density and distribution of ischemic brain damage, and compares these effects to those induced by variations in the duration of ischemia. Body temperatures were maintained at 35 degrees C, 37 degrees C, and 39 degrees C, before, during, and after ischemia, and brain temperatures were held at similar values with a technique that in preliminary experiments proved to avoid intracerebral temperature gradients ...

The two immunosuppressants, cyclosporin A (CsA) and FK506, when given 1 and 3 h after the start of reperfusion following 2 h of middle cerebral artery (MCA) occlusion, reduce infarct volume to 30% of control. This suggests a common effect, e.g. one due to suppression of the activation of calcineurin. However, when given by the intracarotid (i.c.) route after only 5 min of recirculation CsA, but not FK506, reduced infarct volume even further, to 10% of control. This was attributed to the ...

The protein-tyrosine kinases Trk, TrkB, and TrkC are signal-transducing receptors for a family of neurotrophic factors known as the neurotrophins. Here we show that seizures induced by hippocampal kindling lead to a rapid, transient increase of trkB mRNA and protein in the hippocampus. TrkB is a component of a high affinity receptor for brain-derived neurotrophic factor (BDNF). No change was detected in mRNAs for Trk or TrkC, components of the high affinity nerve growth factor or ...