Abstract: | The mechanism of suppression of humoral immune response to dinitrophenylated bovine gamma globulin (DNP23-BGG), human serum albumin (HSA), and trinitrophenylated sheep red blood cells (TNP-SRBC) by 6-mercaptopurine (6-MP) was studied in guinea pigs. Following the intradermal application of the antigens emulsified in complete (CFA) or incomplete Freund's adjuvant (IFA) each test animal was given 6-MP, 10 mg/kg/day for 7 days. This treatment resulted in a significant suppression of the anti BGG and anti SRBC agglutinating and complement binding antibody production. The latter was only significantly suppressed if the TNP-SRBC were applied together with CFA and not if TNP-SRBC were given in IFA. The anti DNP and anti HSA antibody formation was not influenced. |