Roles of adenosine receptors in the regulation of kainic acid-induced neurotoxic responses in mice.
Kainic acid (KA) is a well-known excitatory and neurotoxic substance. In ICR mice, morphological damage of hippocampus induced by KA administered intracerebroventricularly (i.c.v.) was markedly concentrated on the hippocampal CA3 pyramidal neurons. In the present study, the possible role of adenosine receptors in hippocampal cell death induced by KA (0.1 microg) administered i.c.v. was examined. It has been shown that 3,7-dimethyl-1-propargylxanthine (DMPX; A2 adenosine receptors antagonist, 20 microg) reduced KA-induced CA3 pyramidal cell death. KA dramatically increased the phosphorylated extracellular signal-regulated kinase (p-ERK) immunoreactivities (IR) in dentate gyrus (DG) and mossy fibers. In addition, c-Jun, c-Fos, Fos-related antigen 1 (Fra-1) and Fos-related antigen 2 (Fra-2) protein levels were increased in hippocampal area in KA-injected mice. DMPX attenuated KA-induced p-ERK, c-Jun, Fra-1 and Fra-2 IR. However, 1,3-dipropyl-8-(2-amino-4-chlorophenyl)-xanthine (PACPX; A1 adenosine receptor antagonist, 20 microg) did not affect KA-induced p-ERK, c-Jun, Fra-1 and Fra-2 IR. KA also increased the complement receptor type 3 (OX-42) IR in CA3 region of hippocampus. DMPX, but not PACPX, blocked KA-induced OX-42 IR. Our results suggest that p-ERK and c-Jun may function as important regulators responsible for the hippocampal cell death induced by KA administered i.c.v. in mice. Activated microglia, which was detected by OX-42 IR, may be related to phagocytosis of degenerated neuronal elements by KA excitotoxicity. Furthermore, it is implicated that A2, but not A1, adenosine receptors appear to be involved in hippocampal CA3 pyramidal cell death induced by KA administered i.c.v. in mice.
Lee
Han-Kyu
HK
Department of Pharmacology and Institute of Natural Medicine, College of Medicine, Hallym University, 1 Okchun-Dong, Chunchon, Kangwon-Do 200-702, South Korea.
Choi
Seong-Soo
SS
Han
Ki-Jung
KJ
Han
Eun-Jung
EJ
Suh
Hong-Won
HW
D000818:Animals; D016923:Cell Death / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology* / Q000633:toxicity; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000378:metabolism; D051921:Fos-Related Antigen-2; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D007608:Kainic Acid / Q000494:pharmacology* / Q000633:toxicity; D008297:Male; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D013805:Theobromine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014970:Xanthines / Q000008:administration & dosage / Q000378:metabolism; D000099169:Fos-Related Antigen 1
D004268:DNA-Binding Proteins; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D051921:Fos-Related Antigen-2; D007608:Kainic Acid; D020928:Mitogen-Activated Protein Kinases; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018047:Receptors, Purinergic P1; D013805:Theobromine; D014157:Transcription Factors; D014970:Xanthines; D000099169:Fos-Related Antigen 1; C497873:Fosl2 protein, mouse; C057837:3,7-dimethyl-1-propargylxanthine; C046379:1,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine