Influence of triphenyltim acetate on lymphatic tissue and immune responses in guinea pigs

In two experiments an immunosuppressive effect of triphenyltin acetate (TPTA) in female guinea pigs was detected with immunochemic, serologic, histologic, and fluorescent antibody techniques. In the first experiment the animals were given 0 or 15 ppm TPTA in the diet for 49 and 77 days. In the second experiment the animals received the same diet for 104 days. At 21 and 7 days before the end of the TPTA feeding, half of the animals received an injection of tetanus toxoid. Some animals were allowed to recover for 14 days after the 104-day experimental period. Immunochemically and serologically a decreased immunologic response was observed in the TPTA-fed group after tetanus toxoid stimulation, and no signs of recovery were seen after 14 days. No data are available for later stages. In the first experiment, after 77 days, a decrease in plasma cells was observed in the spleen and the cervical, mesenteric, axillary, and popliteal lymph nodes. With the aid of the fluorescent antibody technique a decrease in immunologically active cells in the popliteal lymph nodes of the TPTA-fed animals could be detected in the second experiment. No signs of recovery could be demonstrated after 14 days. In the other lymphatic tissues no differences were observed. It is concluded that TPTA should be regarded as an immunosuppressive agent.