In the human lacrimal gland the type A cell (K or mucous) contributes more to gland volume than the B (G or serous). Histochemical tests and organ culture using radioactive sulfate and glucose showed contradictory results for type A granules—sulfate was taken up in culture but did not stain. Lysozyme was shown to bind sulfate strongly. The granules stain like those of the Paneth cell which also contains lysozyme. Type B granules contain either neutral or acid glycoprotein, the latter being either sialic acid or sulfate, sulfate predominating. A granule may contain one or both types of acid, a cell one or more types of granule. The type A cell is a source of lysozyme, the B of neutral and acid glycoprotein in tears, the latter being a sulfosialomucin.
Allen M, Wright P, Reid L. The Human Lacrimal Gland: A Histochemical and Organ Culture Study of the Secretory Cells. Arch Ophthalmol. 1972;88(5):493–497. doi:10.1001/archopht.1972.01000030495005
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