A role of sigma receptors on hypoxia/hypoglycemia-induced decrease in CA1 presynaptic fiber spikes in rat hippocampal slices.
Effects of sigma receptor agonists or antagonists on hypoxia/hypoglycemia-induced decrease in CA1 presynaptic fiber spikes elicited by the stimulation of Schaffer collaterals were investigated using rat hippocampal slices. Treatment with sigma receptor antagonists such as haloperidol, NE-100 and rimcazole produced a concentration-dependent attenuation of the hypoxia/hypoglycemia-induced decrease in CA1 presynaptic fiber spikes. The order of potency of protection against hypoxia/hypoglycemia-induced reduction in CA1 presynaptic potential was: NE-100 = haloperidol > rimcazole. Treatment with sigma receptor agonist DTG potentiated the hypoxia/hypoglycemia-induced decrease in the CA1 presynaptic potential, whereas SKF10047 which possesses an affinity for phencyclidine site attenuated the decrease of potential. NE-100 antagonized a functional deficit induced by DTG, but unaffected the improving effect induced by SKF10047. The present results suggest a facilitatory role of sigma receptor stimulation in hypoxia/hypoglycemia-induced an impairment of neurophysiological functions in CA1 presynaptic regions of hippocampal slices.
Shibata
S
S
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University 62, Fukuoka, Japan.
Yamamoto
Y
Y
Watanabe
S
S
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000840:Anisoles / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology*; D007003:Hypoglycemia / Q000503:physiopathology*; D002534:Hypoxia, Brain / Q000188:drug therapy / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology*; D017729:Presynaptic Terminals / Q000187:drug effects / Q000502:physiology*; D011437:Propylamines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017480:Receptors, sigma / Q000187:drug effects / Q000502:physiology*
D000840:Anisoles; D006146:Guanidines; D011437:Propylamines; D017480:Receptors, sigma; C083832:N,N-dipropyl-2-(4-methoxy-3-(2-phenylethoxy)phenyl)ethylamine monohydrochloride; D006220:Haloperidol; C050232:1,3-ditolylguanidine