P4112 and P4114, derivatives of betamethasone and methylprednisolone, respectively, are more potent in reducing rat peritoneal cell numbers and activity

It was investigated whether P4112 and P4114, derivatives of the steroids be tamethasone and methylprednisolone, respectively, were more potent in 1) re ducing cell numbers in the rat peritoneal cavity and in 2) suppressing the production of reactive oxygen species as measured by chemiluminescence. Rat s were injected intra peritoneally with betamethasone, methylprednisolone, P4112, P4114 (10 mg/kg) or with solvent solution. After 48 hours, the perit oneal cavity was lavaged. Betamethasone reduced the number of cells by 40% as compared to controls. Interestingly, P4112 was twice as potent as betame thasone. Similar results were obtained with methylprednisolone and P4114. T his was mainly due to a decrease in the number of macrophages and eosinophi ls. Furthermore, P4112 and P4114, and not the lead steroids, suppressed bas al and stimulated chemiluminescence production. It can be concluded that bo th P4112 and P4114 are more potent than the lead steroids.