Rw. Luebke et al., HOST-RESISTANCE TO TRICHINELLA-SPIRALIS INFECTION IN RATS EXPOSED TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD), Fundamental and applied toxicology, 24(2), 1995, pp. 285-289
We have previously shown decreased resistance to Trichinella spiralis
(Ts) infection and reduced parasite antigen-specific responses in B6C3
F1 mice exposed to TCDD before infection. The current study was done t
o characterize the effects of preinfection administration of 1, 10, or
30 mu g TCDD/kg on host resistance of female F344 rats to Ts infectio
n and to examine parasite antigen-specific responses in the spleen and
mesenteric lymph nodes of infected animals. TCDD exposure did not aff
ect adult parasite elimination from the small intestine or the numbers
of encysted larvae in the muscle, although host control of newborn la
rvae production in female parasites isolated from the highest dose gro
up was compromised, Proliferative responses of lymphocytes cultured wi
th parasite antigen were enhanced in groups of rats exposed to 30 mu g
TCDD/kg. These results, which are in marked contrast to the effects o
btained in B6C3F1 mice, demonstrate a clear species difference in the
effects of TCDD on immune function in rodents and underscore the need
to determine which species more closely reflects the potential outcome
of human exposure to TCDD. (C) 1995 Society of Toxicology.