Changes in non-heme iron histochemistry in the ischemic brains of cats and Mongolian gerbils

We studied the changes in non-heme iron histochemistry in the ischemic brains of the cat and Mongolian gerbils. For the histochemical visualization of non-heme ferric (Fe(III)) and ferrous (Fe(II)) iron, perfusion-Perls and perfusion-Turnbull methods were used. Deeply anesthetized animals were transcardially perfused with the solution containing 1% HCl, 1% potassium ferrocyanide (perfusion-Perls method) or 1% potassium ferricyanide (perfusion-Turnbull method), and 10% formalin. In the non-ischemic animals, perfusion was performed in the cephalic direction through the abdominal aorta or through the ascending aorta within 2 min after thorachotomy and cardiotomy—incision of the right auricle and left ventricle. In the ischemic animals, perfusion was performed through the ascending aorta 10, 20 and 30 min after cardiotomy. Frozen sections of the brain were treated for 3,3′-diaminobenzidine tetrahydrochloride (DAB) intensification of Perls and Turnbull reaction product. It was demonstrated that cytoplasmic Fe(III) was reduced to Fe(II) in oligodendrocytes of ischemic brains, and that Fe(II) was concentrated in the neuronal and glial cell nuclei regardless of the presence or absence of blood supply impairment.