Further 237Pu experiments with the plaice Pleuronectes platessa: Subcellular distribution of plutonium in the liver

The subcellular distribution of ²³⁷Pu in the livers of the plaice Pleuronectes platessa has been studied by differential and isopycnic gradient centrifugation. It has been shown that the ²³⁷Pu is particularly accumulated in pellets sedimenting out at 3000 and 6000 g which, by deduction from marker enzyme tests, contain a mixture of mitochondria and lysosomes. Separation of lysosomes from mitochondria was achieved by using a non-lytic detergent injected into the fish 3 d prior to removal of the livers; it was found that ²³⁷Pu was associated with the lysosomal fraction. In this respect, the metabolism of plutonium of the plaice resembles that of the rat.