Lymphatic tissue response in chickens treated with tri-o-tolyl phosphate

Indices of immunologic response elicited by tri-o-tolyl phosphate (TOTP) in chickens were investigated. Histopathologic evaluation of lymphatic organs (spleen, cecal tonsil, bursa of Fabricius) and selected immuno-related visceral organs containing lymphatic infiltrations (liver, kidney, duodenum, pancreas) was conducted. Liver and spleen showed a consistent and definite increase of diffuse lymphatic tissue in TOTP-treated animals. Total plasma protein levels of treated animals were increased from 7 to 20% over 4-14 days after TOTP administration. A similar increased pattern was noted in gamma-globulin:albumin ratios of the treated group. The data suggested stimulation of immunologic response in chickens treated with TOTP.