Restoration of cyclophosphamide-suppressed primary immune response in mice by Tołpa Peat Preparation (TPP)--comparison with calf thymus extract.

In order to induce pharmacological immunosuppression in Balb/c mice, the animals were given cyclophosphamide intraperitoneally, 200 mg/kg 144 hours or 24 hours prior to SRBC immunization. Tołpa Peat Preparation (TPP) was administered in doses of 10 and 50 mg/kg on the day of immunization and then every 24 hours for 3 consecutive days. It was given both to mice cyclophosphamide-treated and non-treated. Calf thymus extract (TFX) was administered (1 and 5 mg/kg) parallelly, for comparison with TPP. The following immunologic indices were determined: percent of splenocytes forming E- and EAC-rosettes, number of plaque-forming cells (PFC) and the levels of 19S+7S and 7S anti-SRBC haemagglutinins. The immunosuppressing action of a single cyclophosphamide dose decreased the percentage of EAC rosettes, number of PFC and serum anti-SRBC haemagglutinin titre. TPP is able to restore the percent of EAC rosettes, the number of PFC and anti-SRBC haemagglutinin titre, either partially or totally, after cyclophosphamide-induced immunosuppression. The effectiveness of TPP depends mainly on the dose and timing of cyclophosphamide administration prior to SRBC immunization. The most pronounced restoration of the cells in mice was observed with the TPP dose of 50 mg/kg after cyclophosphamide suppression 144 h before immunization. TFX (1 mg/kg) only partially restored the number of PFC and 7S anti-SRBC haemagglutinin titre, which had been depressed due to cyclophosphamide treatment 144 h prior to immunization. However, it did not change the depressing effect of cyclophosphamide on the percent of EAC rosette-forming splenocytes.(ABSTRACT TRUNCATED AT 250 WORDS)