The Gordon phenomenon induced by the eosinophil cationic protein and eosinophil protein X.

Cerebellar Purkinje cell degeneration after intracerebral injection of eosinophil granulocytes or extracts thereof is known as the Gordon phenomenon. The reaction is said to be highly selective. An eosinophil-derived neurotoxin (EDN) has recently been reported to induce the Gordon phenomenon. However, we report here that two eosinophil-derived proteins, eosinophil cationic protein (ECP) and eosinophil protein X (EPX), may induce the Gordon phenomenon after intraventricular injection. The potency of ECP is far greater than that of EPX and the latter is possibly identical to EDN. The Fink-Heimer staining for degenerating nerve fibers and boutons, however, indicated that the selectivity of the Gordon phenomenon is not as specific as was previously thought, since this method revealed degeneration of all brain areas in proximity to the ventricular system.