摘要：

A study of the activity of lysosomal enzymes in the retina and the structural integrity of lysosomes in the pigment epithelium of the normal and dystrophic rat eye was carried out using standard biochemical and cytochemical techniques respectively. The experiments were performed on eyes from rats aged 1–12 weeks which covers the developmental period of the retina and progressive stages of the degeneration. Measurement of total and free lysosomal enzyme activity in the retina was achieved by the use of acid protease as the lysosomal enzyme marker. Increases in both total and "free" activities above those found in the normal retina were first observed in the dystrophic retina at 4 weeks; these differences became more apparent as the degeneration progressed. The stability of lysosomes in the pigment epithelium was studied by measuring the accessibility of the lysosomal enzymes naphthylamidase and acid phosphatase to the respective substrates. It was found that, as early as 1 week of age, the lysosomes in the dystrophic pigment epithelium are less stable than those in the normal tissue. This instability became more pronounced as the animals aged. The results support the hypothesis that the degeneration of the visual cells in inherited retinal dystrophy is initiated by the infiltration of lysosomal enzymes from the pigment epithelium.

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