'In vivo perfusion Turnbull's reaction' for Fe(II) histochemistry in non-anoxic/non-ischemic and anoxic/ischemic cat brains.

We developed a simple but ingenious histochemical method, 'in vivo perfusion-Turnbull's reaction', for the visualization of non-heme Fe(II) of the brain; in situ release of Fe(2+) ions was coupled with formation of insoluble reaction product (Turnbull's blue) by in vivo perfusion of acid ferricyanide through the abdominal (non-anoxic/non-ischemic brain) or ascending (anoxic/ischemic brain) aorta in the deeply anesthetized adult cats. Frozen sections of the brain were treated according to the method of Nyguen-Legros et al. [12] to intensify Turnbull's reaction. The method revealed that cytoplasmic Fe(III) was reduced to Fe(II) in oligodendroglias in anoxic/ischemic (for 20 min) brains, and that Fe(II) was concentrated in the neuronal and glial cell nuclei regardless of the presence or absence of blood supply impairment.