PURPOSE: Topiramate is a novel antiepileptic drug, and is known to act as a glutamate receptor antagonist. Excitotoxicity by glutamate is also advocated as an arm of brain injury in bacterial meningitis. We sought to delineate whether topiramate could attenuate brain energy depletion during bacterial meningitis by near infrared spectroscopy monitoring. METHODS: Meningitis was induced by intracisternal injection of 108 colony forming units of Escherichia coli. Topiramate at a dose of 50 or 100 mg/kg was given to the piglets 30 minutes before the induction of meningitis. The piglets in the meningitis control group were not given topiramate. Cerebral blood volume, cerebral blood flow, and brain cell energy state were monitored for 6 hours by near infrared spectroscopy. RESULTS: 100 mg/kg of topiramate significantly attenuated the increase in intracranial pressure and leukocyte count in the cerebrospinal fluid during study period. Although statistically insignificant, there was a trend of decrease in cerebral blood volume as indicated by total hemoglobin and cerebral blood flow as indicated by oxidized hemoglobin. Deduced hemoglobin in the meningitis was attenuated by topiramate. Topiramate did not significantly affect the brain energy state as indicated by cytochrome aa3 during the 6 hours after the induction of meningitis. CONCLUSION: 100 mg/kg of topiramate significantly attenuated the inflammatory response in experimentally induced bacterial meningitis. However, there was no significant effect of topiramate on the brain cell energy metabolism during the early phase of experimental bacterial meningitis.
Arm ; Blood Volume ; Brain Injuries ; Brain* ; Cerebrospinal Fluid ; Electron Transport Complex IV ; Energy Metabolism* ; Escherichia coli* ; Escherichia* ; Glutamic Acid ; Intracranial Pressure ; Leukocyte Count ; Meningitis ; Meningitis, Bacterial ; Meningitis, Escherichia coli* ; Receptors, Glutamate ; Spectrum Analysis ; Stem Cells

In the present study, we tested whether maintenance of adequate cerebral perfusion pressure (CPP) by pharmacologically preventing systemic hypotension with dopamine infusion would prevent cerebral ischemia and attenuate energy depletion and neuronal injury even though intracranial pressure remains elevated in a newborn piglet meningitis model. Cerebral blood flow, measured at the end of the experiment using fluorescent microspheres, was significantly increased by dopamine infusion. The decreased cerebral cortical cell membrane Na+, K+-ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain damage, were significantly attenuated by dopamine infusion. Dopamine also significantly attenuated the meningitis-induced reduction in both brain ATP and phosphocreatine levels and the increase in brain lactate level. In summary, maintenance of adequate CPP with dopamine prevented cerebral ischemia, reduced cerebral energy depletion, and attenuated brain injury in neonatal bacterial meningitis.
Animals ; Animals, Newborn ; Brain/cytology/drug effects/*physiology ; Cell Membrane/*metabolism ; Cerebrovascular Circulation/*drug effects ; Dopamine/metabolism/*pharmacology ; Fluorescent Dyes/metabolism ; Hemodynamic Processes ; Meningitis, Escherichia coli/*metabolism ; Microspheres ; Random Allocation ; Regional Blood Flow ; Support, Non-U.S. Gov't ; Swine

We evaluated the efficacy of non-competitive N-methyl-D-aspartate receptor antagonist MK-801 (dizocilpine) as an adjuvant therapy in experimental neonal bacterial meningitis. Meningitis was induced by injecting 10(6) colony forming units of Escherichia coli into the cisterna magna. MK-801 3 mg/kg was given as a bolus intravenous injection, 30 min before the induction of meningitis. MK-801 did not down-modulate the inflammatory parameters, such as increased intracranial pressure, cerebrospinal fluid (CSF) leukocytosis, increased lactate and TNF-alpha levels in the CSF, and hypoglycorrhachia observed in the meningitis group. MK-801 did not significantly attenuate the elevated glutamate concentration in the CSF. However, MK-801 showed some neuroprotective effects as evidenced by significant attenuation of cerebral lipid peroxidation products (conjugated dienes) and increase of brain high-energy phosphate compounds (ATP and PCr). Improvement in cerebral cortical cell membrane Na+, K+ -ATPase activity did not reach a statistical significance. These results suggest that MK-801 was effective in ameliorating brain injury in neonatal bacterial meningitis, although it failed to attenuate the inflammatory responses.
Animals ; Animals, Newborn ; Blood Glucose/metabolism ; Brain/cytology ; Brain/drug effects* ; Brain/metabolism ; Cell Membrane/drug effects* ; Cell Membrane/metabolism ; Cerebral Cortex/metabolism ; Dizocilpine Maleate/pharmacology* ; Energy Metabolism* ; Excitatory Amino Acid Antagonists/pharmacology ; Glutamic Acid/cerebrospinal fluid ; Lactic Acid/blood ; Leukocytes/metabolism ; Meningitis, Escherichia coli/drug therapy ; Meningitis, Escherichia coli/metabolism* ; Neurons/drug effects* ; Neurons/metabolism ; Neuroprotective Agents/pharmacology* ; Random Allocation ; Swine ; Tumor Necrosis Factor/cerebrospinal fluid

In this study, we tested the hypothesis that decreased cerebral perfusion pressure (CPP) induces cerebral ischemia and worsen brain damage in neonatal bacterial meningitis. Meningitis was induced by intracisternal injection of 10(9) colony forming units of Escherichia coli in 21 newborn piglets. Although CPP decreased significantly at 8 hr after bacterial inoculation, deduced hemoglobin (HbD), measured as an index of changes in cerebral blood flow by near infrared spectroscopy, did not decrease significantly. In correlation analyses, CPP showed significant positive correlation with brain ATP and inverse correlation with brain lactate levels. CPP also correlated positively with HbD and oxidized cytochrome aa3 (Cyt aa3) by near infrared spectroscopy. However, CPP did not show significant correlation with cerebral cortical cell membrane Na+,K+-ATPase activity, nor with levels of lipid peroxidation products. In summary, decreased CPP observed in this study failed to induce cerebral ischemia and further brain injury, indicating that cerebrovascular autoregulation is intact during the early phase of experimental neonatal bacterial meningitis.
Animal ; Animals, Newborn ; Blood Glucose/metabolism ; Cell Membrane/microbiology ; Cell Membrane/enzymology ; Cerebral Cortex/metabolism ; Cerebral Cortex/chemistry ; Cerebral Cortex/blood supply ; Cerebrovascular Circulation/physiology* ; Energy Metabolism/physiology* ; Escherichia coli Infections/physiopathology* ; Escherichia coli Infections/metabolism* ; Glucose/cerebrospinal fluid ; Glucose/analysis ; Intracranial Pressure ; Lactic Acid/cerebrospinal fluid ; Lactic Acid/blood ; Lactic Acid/analysis ; Lipid Peroxidation/physiology ; Meningitis, Bacterial/physiopathology* ; Meningitis, Bacterial/metabolism* ; Na(+)-K(+)-Exchanging ATPase/metabolism ; Spectroscopy, Near-Infrared ; Swine

OBJECTIVETo explore the neuro-protective effect and mechanism of qingkailing injection (QKL) against cerebral injury caused by E. coli-meningitis (CM).

METHODSThe CM model rabbits were treated by ampicillin with QKL as adjuvant. The leukocyte count and protein content in cerebral spinal fluid (CSF), the contents of water, sodium, potassium and calcium in cerebral tissues were measured before, 16 h and 26 h after Bacillus coli injection respectively. The expression of matrix metalloproteinase-9 (MMP-9) was determined at the same time.

RESULTSAdjunctive treatment with QKL can not only inhibit the increase of leukocyte cells, protein content in CSF, and water, sodium, calcium content in cerebral tissues, but also the decrease of potassium content revealed during simple antibiotic treatment. It also can decrease the expression of MMP-9 in cerebral tissues of rabbits with CM.

CONCLUSIONAs an adjunctive treatment, QKL can prevent transient inflammatory reaction and aggravation of brain injury in CM induced by simple antibiotic treatment, its mechanisms might relate with calcium antagonism and attenuation of MMP-9 expression in brain tissues.

Ampicillin ; therapeutic use ; Animals ; Anti-Bacterial Agents ; therapeutic use ; Brain ; metabolism ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Injections ; Male ; Matrix Metalloproteinase 9 ; biosynthesis ; Meningitis, Escherichia coli ; drug therapy ; Neuroprotective Agents ; therapeutic use ; Phytotherapy ; Rabbits