The lysosomal enzymes of the iris-ciliary body are retained in their organelles and exhibit increased activities during acute uveal inflammation.

Acute uveal inflammation, characterised by conjunctival hyperaemia, limbal vascular injection, iritis and aqueous flare, was induced in the rabbit eye by a single intravitreal injection of 10 micrograms of Shigella endotoxin. Twenty-four, 48 and 72 h after endotoxin administration, lysosomal-rich fractions and cytosolic supernatants were prepared from iris-ciliary bodies and the enzymatic activities of some lysosomal hydrolases in these fractions were assayed. Acid phosphatase, aryl sulphatase and N-acetyl-B-D-glucosaminidase exhibited increased activities in the lysosomal preparations from inflamed iris-ciliary bodies, relative to the activities of the same enzymes in lysosomal fractions from normal iris-ciliary bodies. No significant differences in activities were obtained for these enzymes in cytosolic supernatants from normal and inflamed iris-ciliary bodies. The results suggest that during acute ocular inflammation the lysosomal hydrolases are retained in their organelles at an elevated state of activity.