dizocilpine-maleate and fructose-1-6-diphosphate

D-fructose-1,6-bisphosphate, a high energy glycolytic intermediate, attenuates ischemic damage in a variety of tissues, including brain. To determine whether D-fructose-1,6-bisphosphate serves as an alternate energy substrate in the CNS, rat hippocampal slices were treated with D-fructose-1,6-bisphosphate during glucose deprivation. Unlike pyruvate, an endproduct of glycolysis, 10 mM D-fructose-1,6-bisphosphate did not preserve synaptic transmission or morphological integrity of CA1 pyramidal neurons during glucose deprivation. Moreover, during glucose deprivation, 10-mM D-fructose-1,6-bisphosphate failed to maintain adenosine triphosphate levels in slices. D-fructose-1,6-bisphosphate, however, attenuated acute neuronal degeneration produced by 200 microM iodoacetate, an inhibitor of glycolysis downstream of D-fructose-1,6-bisphosphate. Because (5S, 10R)-(+)-5-methyl-10, 11-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine, an antagonist of N-methyl-D-aspartate receptors, exhibited similar protection against iodoacetate damage, we examined whether (5S, 10R)-(+)-5-methyl-10, 11-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine and D-fructose-1,6-bisphosphate share a common neuroprotective mechanism. Indeed, D-fructose-1,6-bisphosphate diminished N-methyl-D-aspartate receptor-mediated synaptic responses and partially attenuated neuronal degeneration induced by 100-microM N-methyl-D-aspartate. Taken together, these results indicate that D-fructose-1,6-bisphosphate is unlikely to serve as an energy substrate in the hippocampus, and that neuroprotective effects of D-fructose-1,6-bisphosphate are mediated by mechanisms other than anaerobic energy supply.

Topics: Adenosine Triphosphate; Animals; Dizocilpine Maleate; Energy Metabolism; Excitatory Amino Acid Antagonists; Excitatory Postsynaptic Potentials; Fructosediphosphates; Glucose; Hippocampus; Neurons; Neuroprotective Agents; Organ Culture Techniques; Pyruvic Acid; Rats; Receptors, N-Methyl-D-Aspartate; Synaptic Transmission

To investigate whether the protective effect of therapy with different combined neuroprotectant agents was better than that of single agent on focal cerebral ischemia.. The right middle cerebral artery in the rats was occluded with suture occlusion technique. The rats were divided into five groups treated with FDP (50 mg/kg, n = 10), MK-801 (1 mg/kg, n = 10) and NAC (150 mg/kg, n = 10) singly, or in combination, respectively, by intraperitoneal infusion 30 minutes after vessel occlusion. The rats were weighed and assessed neurologically, based on a 5-point scale, six and 24 hours after focal cerebral ischemia. The expression of anti-apoptotic protein bcl-2 was observed with SDS-PAGE protein electrophoresis and Western blot technique.. The optical density of bcl-2 increased more distinctly in the rats treated with combined neuroprotective agents than that with any single agent six and 24 hours after cerebral ischemia, with a statistically significant difference (P < 0.05).. Treatment with combined neuroprotectant agents could un-regulate the anti-apoptotic protein bcl-2 more distinctly than that with any single agents. Combined use of neuroprotectants might be more effective than that of single agent in protecting rats' brain from ischemia.

Topics: Acetylcysteine; Actins; Animals; Brain Ischemia; Dizocilpine Maleate; Drug Therapy, Combination; Fructosediphosphates; Male; Molecular Weight; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar