Effect of betamethasone in lungs of mice treated with lymphocytosis-promoting factor of Bordetella pertussis.

The role of betamethasone in the lungs of mice treated with lymphocytosis-promoting factor (LPF) was studied. Intravenous injection with 10 ng of LPF produced significant lymphocytosis and monocytosis five days later. Two groups were also treated with betamethasone: the first with daily administrations and the second at zero-time with LPF. Lymphocytosis was not as high as in the group treated only with LPF (P less than .05), and lymphocytosis was lower in the second group than in the first (P less than .05). In lungs of mice treated with LPF, lymphocytes accumulated relative to lymphoid organs such as the spleen, where a marked depletion was noted. Administration of betamethasone either with LPF or after one day did not cause accumulation of lymphocytes in lungs, whereas increased spleen cellularity was observed. These data were also supported by histological changes, i.e., diminished congestion and edema of the lung and reduction of mononuclear cells in parenchyma.