Interleukin-1/3 mRNA Expression inIschemic RatCortex

Background and Purpose: Interleukin-1lj isa proinflammatory cytokine produced byblood-borne and resident brain inflammatory cells. Thepresent study was conducted todetermine ifinterleukin-13 mRNA was produced inthebrainofratssubjected topermanent focal ischemia. Methods: Ratinterleukin-lj cDNA,synthesized fromstimulated ratperitoneal macrophage RNA by reversetranscription andpolymerase chainreaction andcloned inplasmid Bluescript KS+,was usedto evaluate theexpression ofinterleukin-1.3 mRNA incerebral cortex fromspontaneously hypertensive rats andnormotensive ratssubjected topermanent middlecerebral artery occlusion. Interleukin-1f3 mRNA was quantified byNorthern blotanalysis andcompared withratmacrophage RNA standard. Tocorrect forgelloading, blots werealsoanalyzed withcyclophilin cDNA,whichencodes an abundant, conserved protein that was unchanged bytheexperimental conditions. Results: Interleukin-10 mRNA produced intheischemic zonewas significantly increased from6 hours to120hours, withamaximumof211±24%ofinterleukin-lf reference standard, ie, 0.2ngstimulated rat macrophage RNA,mRNA compared withthelevel innonischemic cortices (4±2%)at12hoursafter ischemia (P<.01; n=6).Interleukin-1f3 mRNA at12hoursafter ischemia was markedly elevated in hypertensive ratsoverlevels foundintwonormotensive ratstrains. Neurological deficits were also apparent onlyinthehypertensive rats. Conclusions: Braininterleukin-1j3 mRNA iselevated acutely afterpermanent focalischemia and especially inhypertensive rats. Thesedatasuggest thatthispotent proinflammatory andprocoagulant cytokine mighthavea roleinbraindamagefollowing ischemia. (Stroke. 1993;24:1746-1751.)