Ultrastructure of choroid plexus of the rat brain after 2,4-dinitrophenol treatment

The effect of 2,4-dinitrophenol on the lateral ventricles choroid plexus of the rat was investigated at ultrastructural level. Following 7 min. ventriculo-cisternal continuos perfusion with CSF mock solution containing 1 mM DPN, slight hydration of the hyaloplasm and condensation of mitochondria and of Golgi complex were observed. After longer treatment, 15 min. there was marked hydration of whole ependymal cells, swollen mitochondria, enlarged cisterns of Golgi apparatus and RER, and considerable extension and hydration of perivascular and intercellular spaces. These changes seem to arise from DNP action on the ependymal mitochondria. Uncoupling of oxidative phosphorytalion, a known action of DNP, may have blocked energy donation for ion pump and stopped it function. Selectiveness of choroid plexus barrier to ion transport would then disappear and vast changes in the permeabiltiy of cell membranes occur.