Studies of human tear proteins. 3. Distribution of specific tear prealbumin in lacrimal glands and other ocular adnexa.

Tear fluid is a mixed solution containing many kinds of proteins, and two predominant fractions have been determined by electrophoretic studies. One is anodal specific tear prealbumin (STP) and the other is cathodal lysozyme. This study is the first to demonstrate the localization of STP in the ocular adnexa by the immunofluorescence method. STP was found in the acinar cells of both the main and the accessory lacrimal glands. The cells of the interlobular ducts showed no or only weak staining of STP. No specific staining of STP was found in the conjunctiva, cornea or Meibomian gland. STP as well as lysozyme are thought to be secreted from the main and the accessory lacrimal glands.