SYNTHESIS OF GROUP-II PHOSPHOLIPASE-A2 AND LYSOZYME IN LACRIMAL GLANDS

Purpose. The aim of this study was to demonstrate the synthesis and ce llular distribution of group IT phospholipase A2 and lysozyme in the m ain and accessory lacrimal glands. Methods. The authors studied sample s of normal main lacrimal glands of seven autopsied subjects and acces sory lacrimal glands of eight patients who underwent ptosis surgery. T he specimens were immunostained with a rabbit antiserum against group II phospholipase A2 and a monoclonal antibody against lysozyme. Expres sion of group II phospholipase A2 gene was shown using Northern hybrid ization and in situ hybridization. Results. Lysozyme was present in th e secretory granules of most acini, whereas group IT phospholipase A2 was seen in a minority of acinar cells, primarily in the central parts of lobules in the main and accessory lacrimal glands. Synthesis of gr oup II phospholipase A2 in the glandular cells was confirmed by Northe rn hybridization and by in situ hybridization. Conclusions. There are two specialized cell types in the main and accessary lacrimal glands, one synthesizing group II phospholipase A2 and the other synthesizing lysozyme. These enzymes are important nonspecific antibacterial factor s in tears.