Cytochrome P-450, Drug Metabolizing Enzymes and Arachidonic Acid Metabolism in Pig Ocular Tissues

ABSTRACT

The eye is a relatively isolated organ and tends to retain or accumulate compounds within itself. Unless the eye possesses a mechanism for detoxifying drugs and chemicals that are carried to ocular tissues via the circulating blood, the compounds may cause visual impairment. The purposes of this experiment was judged by drug metabolizing action by cytochrome P-450 system, distribution and effect of metabolism of arachidonic acid and distribution of lipid peroxide formation and phospholipids in the lens, cornea and choroid-retina of pig ocular tissues. The results were as follows 1. The activities of mixed-function oxidase, cytochrome P-450 and NADPH-cytochrome C reductase were the highest in the choroid-retina compared to the lens and cornea. 2. The activities of drug metabolizing enzymes, aryl hydrocarbon hydroxylase, 7-ethoxycoumarin-o-deethy lase and benzphetamine-N-demethy lase, heme oxygenase activity, and the activity of arachidonic acid metabolizing enzyme, cyclooxygenase were the highest in the choroid-retina compared to the lens and cornea. 3. Lipid peroxide formation was the highest in the cornea compared to the lens and choroid retina. 4. In distribution of phospholipids, sphingomyelin and phosphatidylcholine were the highest in the choroid-retina compared to the lens and cornea and phosphatidylethanolamine was the highest in the cornea campa red to the lens and choroid-retina. 5. Cytochrome P-450 isoenzyme of pig ocular tissues was confirmed in the same form of MAb(Monoclonal Antibody) PCN(pregenolone-16alpha-carbonitrile) 213-1.