Effect of interleukin-2 on salivary gland morphology and function in mice

C57BL mice were injected intraperitoneally with 300,000 Cetus units/day of human recombinant interleukin-2 (rIL-2) for 2, 4, and 5 days to study its effect on salivary gland function and morphology. The pilocarpine-stimulated parotid salivary flow was collected via cannulation of the glandular duct. Total salivary protein was assayed spectrophotometrically, salivary electrolytes were determined by atomic absorption, and glandular lymphoid cell infiltration was evaluated histologically. After 5 days of rIL-2 administration salivary output and total salivary protein concentrations were reduced significantly. Similar changes, albeit to a lesser extent, were observed following 2 and 4 days of rIL-2 treatment. Increased lymphoid infiltration of the salivary glands was observed, and was directly related to the duration of rIL-2 administration. The effect of the lymphokine on the parotid gland gradually dwindled after cessation of treatment: 4 days posttreatment this salivary gland showed signs of recovery, which at 10 days proved to be complete. The possible use of this animal model in the study of lymphocyte-induced salivary gland diseases is discussed.