Abstract
The in vivo effects of prednisolone 17-valerate 21-acetate (PVA), an anti-inflammatory glucocorticoid on several immunological responses in mice were investigated in comparison with hydrocortisone 17-butyrate (HB) and betamethasone 17-valerate (BV), when given subcutaneously. PVA reduced the spleen weight, the number of splenic nucleated cells, the formation of hemolytic plaque forming cells (PFC), delayed type footpad reaction and the responsiveness of splenic lymphocytes to concanavalin A. These suppressive effects were almost the same as those seen with HB and weaker than those of BV. However, the responsiveness of splenic cells to lipopolysaccharide and circulating IgM antibody response to sheep red blood cells were suppressed by a smaller dose of PVA than that of HB. PVA had no effect on the responsiveness to phytohemagglutinin-P, whereas HB and BV enhanced the phytohemagglutinin-P reponsiveness. The suppressive effect of PVA on the host defense to experimental infection with Escherichia coli was weaker than those of HB and BV. From these results, PVA appears to be similar to other glucocorticoids in that it exerts complicated effects on several immunological responses in mice.