NMDA receptor mediated changes in IGF-II gene expression in the rat brain after injury and the possible role of nitric oxide.
This study was undertaken in order to investigate the role of insulin-like growth factor (IGF)-II, c-fos, N-methyl-D-aspartate (NMDA) receptors, and nNOS in the cellular processes following a penetrating brain injury. IGF-II mRNA levels, as determined by Northern analysis, were decreased at 4, 8, and 24 h after brain injury, in the lesioned, compared to the contralateral intact hemisphere. Forty-eight and 72 h after the injury, there was no difference between the lesioned and the contralateral intact hemisphere in IGF-II mRNA levels. c-fos mRNA levels followed a parallel, but opposite course: They were increased at 4, 8 and 24 h after the injury, while at 48 and 72 h c-fos mRNA levels in the lesioned hemisphere did not differ from those in the intact. Administration of MK-801 reversed the injury-induced decrease in IGF-II mRNA levels. Administration of MK-801 resulted in an increase in IGF-II mRNA in both the intact and the lesioned hemispheres. Brain injury resulted in an increase in nNOS immunopositive cells in the hippocampal formation, which was detectable at 4 and 12, but not 48 h after the injury. These results suggest that IGF-II, c-fos, NMDA receptors and nNOS are involved in the cellular responses to brain injury.
Giannakopoulou
M
M
Laboratory of Biology-Biochemistry, Faculty of Nursing, University of Athens, Athens, Greece.
Mansour
M
M
Kazanis
E
E
Bozas
E
E
Philpipidis
H
H
Stylianopoulou
F
F
D000818:Animals; D001930:Brain Injuries / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D015870:Gene Expression / Q000502:physiology*; D006624:Hippocampus / Q000201:enzymology / Q000473:pathology; D007150:Immunohistochemistry; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D008297:Male; D009474:Neurons / Q000201:enzymology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D013997:Time Factors
D018691:Excitatory Amino Acid Antagonists; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D009569:Nitric Oxide; D007335:Insulin-Like Growth Factor II; D016291:Dizocilpine Maleate; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat