Chronic treatment with sabeluzole protects cultured rat brain neurons from the neurotoxic effects of excitatory amino acids

Abstract

The neuroprotective properties of the cognitive enhancer sabeluzole were investigated in rat brain neuronal cultures derived from the hippocampal formation of 17-day-old rat embryos. Measurement of the neuronal cytoskeletal microtubule-associated protein, MAP2, was used to assess survival of neurons after exposure of neuronal cultures to glutamate. MAP2 was quantified in neuronal cell homogenates by means of an enzyme-linked immunosorbent assay (ELISA) using a mouse monoclonal MAP2 antibody, peroxidase-labeled goat anti-mouse Ig antiserum, and 2,2'-azido-di-[3-ethylbenz-thiazoline] sulphonate (ABTS) as substrate. Exposure of 7-day-old neuronal cultures to 1 mM glutamate for 16 hours led to a three-fold increase in released lactate dehydrogenase (LDH) and a 40% decrease in cellular MAP2 content. Acute treatment of neuronal cultures with 10 microM sabeluzole yielded a 40% drop in released LDH induced by glutamate. Cultures treated chronically with 0.1 microM sabeluzole on days 1 and 4 in culture showed, after 1 week in culture, a MAP2 content and total LDH activity that was not different from control cultures. A 16-hour exposure to 1 mM glutamate did not induce LDH release or changes in MAP2 levels in sabeluzole-treated cultures. A single treatment with 0.1 microM sabeluzole between day 1 to 5 induced a 70-80% drop in glutamate-induced released LDH in 7-day-old neuronal cultures. Full and partial neuronal protection after chronic sabeluzole treatment at 0.1 microM was also observed for neurotoxicity induced by 5 mM N-methyl-D-aspartate (NMDA) and 1 mM kainic acid or 30 microM veratridine, respectively. Within a series of compounds such as Ca++ and Na+ channel antagonists, glutamate receptor antagonists and various neurotransmitter receptor antagonists, sabeluzole, chronically given, were the most potent for inhibition of released LDH induced by 1 mM glutamate (IC50-value: 34 +/- 13 nM). In conclusion, chronic sabeluzole treatment protects cultured rat brain neurons from excitotoxic aggression.

Antiamnesic and Neuroprotective Effects of Donepezil against Learning Impairments Induced in Mice by Exposure to Carbon Monoxide Gas

“…On the other hand, 1 receptor agonists have also been reported to possess neuroprotective effects (for review, see Maurice et al, 1999b). In particular, 1 receptor ligands protected rat hippocampal and cortical neurons against glutamate or NMDA exposure in vitro (Pauwels et al, 1992) or against transient focal or permanent global ischemia in vivo (O'Neill et al, 1995;Harukuni et al, 2000). Interestingly, 1 receptor agonists including igmesine significantly protected Fig.…”

Parathyroid Hormone-related Peptide Is Produced by Cultured Cerebellar Granule Cells in Response to L-type Voltage-sensitive Ca2+ Channel Flux via a Ca2+/Calmodulin-dependent Kinase Pathway

“…This fact is also the likely (but untested) explanation for the observation that NMDA receptor stimulation produced PTHrP mRNA only when added to 15K medium and not to nondepolarizing 5K medium, since the requirements for mildly depolarizing conditions for NMDA activation of its receptor have been observed in this system by others (25). Although veratridine treatment produced a large intracellular calcium flux, none of it was through the L-VSCC, and this same conclusion has been reached by other investigators studying different neuronal culture model systems (38,39). It thus appears that the lack of L-VSCC-mediated Ca 2ϩ flux explains why veratridine treatment does not induce PTHrP mRNA.…”

Neuroprotective sigma ligands interfere with the glutamate‐activated NOS pathway in hippocampal cell culture

“…Neuronal cell culture Primary embryonic hippocampal cultures were prepared essentially as described previously (Pauwels et al, 1992), with minor modifications. Hippocampal formations of rats at embryonic day 17 were dissected and dissociated in 0.05% trypsin and 0.1 mg/ml DNase I in DMEM.…”

“…Cells were plated at a density of 5.3 x 105/cm2 on Petri dishes (56 cm) coated with poly-L-lysine as described previously (Pauwels et al, 1992). On day 7 or 8 of culture, the cells were washed with Ca2+ and M 2 + free PBS.…”