Increase in cortical procholecystokinin gene expression induced by a meningo-cortical injury: studies on the involvement of the "immediate early gene" c-fos.
In rat cortex, a meningo-cortical injury causes complex changes in the expression of the "immediate early" genes c-fos and c-jun as well as the neuropeptide gene procholecystokinin. Within 1 h, mRNA levels of c-fos and c-jun are enhanced. Three hours later they have returned to control values. Twenty-four hours after the injury, there is a second rise in the level of c-fos-mRNA, which is accompanied by an increase in procholecystokinin-mRNA. In the present study, it was investigated whether these events are causally connected. When MK-801 (1.5 mg/kg), an ion-channel blocker, was injected 7 and 19 h after the injury, i.e. after the first rise in expression of both "immediate early" genes, it prevented the later increase in procholecystokinin-mRNA. When given 30 min prior to the injury, MK-801 (4 mg/kg) prevented the increased expression of c-fos but did not affect the later rise in procholecystokinin-mRNA. In a third experiment the cortex injury was performed in a manner which did not increase procholecystokinin-mRNA in frontal cortex. Nevertheless, expression of the c-fos gene was enhanced when determined 24 h after the operation. It is concluded that the injury-induced rise in the expression of the procholecystokinin gene is not connected with the changes in c-fos-mRNA.
Department of Pharmacology, University of Freiburg, Germany.
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Olenik
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Uhl
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Thate
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Meyer
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000293:injuries* / Q000378:metabolism*; D002766:Cholecystokinin / Q000235:genetics*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D017781:Genes, Immediate-Early; D016762:Genes, fos; D016758:Genes, jun; D007700:Kinetics; D008297:Male; D008578:Meninges / Q000293:injuries*; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D011498:Protein Precursors; D012333:RNA, Messenger; D016291:Dizocilpine Maleate; C060249:procholecystokinin; D002766:Cholecystokinin