licostinel and Cerebral-Infarction

A series of analogues of the indole-2-carboxylate GV150526, currently in clinical trials as a potential neuroprotective agent for the control of the cerebral damage after stroke onset, was designed based on previous studies dealing with the electronic features of the north-east region of the glycine binding site associated with the NMDA receptor. In particular, the substitution of the para position of the terminal phenyl ring of GV150526 with suitable hydrophilic groups resulted in the identification of a new class of glycine antagonists. These compounds exhibited nanomolar in vitro affinity to the glycine binding site, high receptor selectivity, and outstanding in vivo potency. In particular, 3-[(E)-2-[(4-ureidomethylphenyl)aminocarbonyl]ethenyl]-4, 6-dichloroindole-2-carboxylic acid was found to be highly effective in the middle cerebral artery occlusion (MCAo) model in the rat, an animal model of focal ischemia, when given both prior to and after the occlusion of the middle cerebral artery. Notably, a significant neuroprotective effect was seen in this model postischaemia, when the administration of this compound was delayed up to 6 h from the occlusion of the middle cerebral artery, further confirming the wide therapeutic window seen for GV150526A.

Topics: Animals; Anticonvulsants; Binding Sites; Brain Ischemia; Carboxylic Acids; Cerebral Infarction; Disease Models, Animal; Glycine; Glycine Agents; Indoles; Mice; Molecular Structure; Neuroprotective Agents; Protein Binding; Rats; Rats, Sprague-Dawley; Receptors, Glycine; Receptors, N-Methyl-D-Aspartate; Urea

Several lines of inquiry have indicated that glycine plays an important role in both glutamatergic neurotransmission and pathophysiology of cerebral ischemia. However, subacute outcome trials demonstrating the efficacy of glycine antagonists as neuroprotectants have not been performed with rigorous control of brain temperature. In this study, we investigated the effect of N-methyl-D-aspartate (NMDA) receptor glycine recognition site antagonism in a temperature-controlled rodent model of transient focal ischemia. Male Wistar rats underwent 75 min of intraluminal middle cerebral artery occlusion (MCAO). During MCAO and the first 24 h of reperfusion, rats (n = 10) were administered e55-nitro-6,7-dichloro-2,3-quinoxalinedione (ACEA 1021) i.v. as a bolus infusion of 5 mg/kg followed by 3.5 mg/kg/h (Low-Dose) or 10 mg/kg followed by 7 mg/kg/ h (High-Dose) for 24 h. Cortical temperature was controlled at 38.0 +/- 0.1 degrees C during MCAO and the first 6 h of reperfusion. A 7-day recovery interval was allowed. Mean total infarct volume was reduced by approximately 40% in both high- and low-dose groups (p < 0.01). The preponderance of infarct reduction occurred in the cortex (p < 0.01). Neurologic function correlated with the size of cerebral infarct (p = 0.001). Neurologic grade was similarly improved by treatment with either dose (p = 0.01). These results demonstrate that neuroprotection achieved by antagonism of the glycine recognition site persists when brain temperature is controlled, indicating a potent mechanism of action other than attenuating a hyperthermic response to ischemia.

Topics: Animals; Binding Sites; Brain Damage, Chronic; Brain Ischemia; Cerebral Infarction; Excitatory Amino Acid Antagonists; Fever; Glycine; Male; Neuroprotective Agents; Quinoxalines; Rats; Rats, Wistar; Receptors, N-Methyl-D-Aspartate; Temperature