Intraventricular infusion of the selective sigma-agonist 1,3-di-ortho-tolylguanidine (DTG) mitigates ischaemic brain damage in the hippocampus.
Experimental evidence suggests that neuronal pharmacologic sites termed sigma (sigma) may be related, but not identical to PCP sites in the ion channel linked to NMDA excitatory receptors. These receptors may play a role in schizophreniform psychoses, and clinical trials of putative sigma-ligands have begun. Because of this, and because of the relationship of sigma-ligands to NMDA receptors, we studied the effect of the most selective presently available sigma-ligand on ischaemic neuronal death throughout the rat brain after transient forebrain ischaemia. Ventricular delivery of DTG at 0.5 mumol/h via an osmotic minipump was chosen to allow continuous access of the drug to brain tissue, control animals receiving artificial CSF. After one week survival, selective neuronal necrosis was reduced in the hippocampus, but not in the neocortex or striatum, contrasting with our previous findings in this model with pure NMDA antagonists. The results indicate that ischaemic neuronal necrosis in the hippocampus may be mitigated by sigma-agonists, possibly via an interaction with NMDA receptors.
Neuroscience Research Group, University of Calgary, Alberta, Canada.
M L
ML
Jensen
R N
RN
Auer
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy* / Q000473:pathology; D002552:Cerebral Ventricles; D002648:Child; D006146:Guanidines / Q000627:therapeutic use*; D006624:Hippocampus; D006801:Humans; D007263:Infusions, Parenteral; D009336:Necrosis; D009474:Neurons / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D011957:Receptors, Opioid / Q000187:drug effects*; D017480:Receptors, sigma
D006146:Guanidines; D016194:Receptors, N-Methyl-D-Aspartate; D011957:Receptors, Opioid; D017480:Receptors, sigma; C050232:1,3-ditolylguanidine