Assessment of the immunotoxic potential of trichloroethylene and perchloroethylene in rats following inhalation exposure

Figures & data

Table 1.  General design for TCE and PERC inhalation studies outlining separate groups of animals for evaluation of the SRBC antibody response.

Exposure concentrations	Number of rats/exposure level
	BAL, hematology, histopathology, organ weights	SRBC antibody response
0 ppm	8	8
0 ppm and CYP	8/0^a	8
100 ppm	8	8
300 ppm	8	8
1000 ppm	8	8
Total # of animals	40/32^a	40

CYP, cyclophosphamide (immunosuppressive positive control).

^a A CYP control group for evaluation of BAL, hematology, histopathology, and organ weights was not included in the PERC study.

Table 2.  Terminal body weights and absolute and relative organ weights for animals exposed to TCE.

Concentration TCE (ppm)		Final body weight (g)	Kidney		Liver		Spleen		Thymus
			(g)	(g/100)	(g)	(g/100)	(g)	(g/100)	(g)	(g/100)
0	Mean	217.2	1.756	0.809	7.01	3.228	0.479	0.219	0.373	0.172
	SD	20.3	0.217	0.072	0.874	0.236	0.096	0.025	0.069	0.028
0 + CYP	Mean	219.1	1.847	0.844	7.197	3.279	0.327*	0.150*	0.135*	0.061*
	SD	21.1	0.220	0.063	0.920	0.175	0.053	0.023	0.034	0.011
100	Mean	212.4	1.818	0.857	7.058	3.324	0.526	0.247	0.399	0.187
	SD	10.5	0.113	0.064	0.441	0.164	0.078	0.031	0.088	0.038
300	Mean	203.9	1.787	0.876	7.042	3.441	0.482	0.237	0.359	0.175
	SD	18.4	0.230	0.082	1.090	0.309	0.056	0.022	0.095	0.042
1000	Mean	206.9	1.969	0.950*	7.580	3.650*	0.451	0.218	0.331	0.159
	SD	13.5	0.253	0.081	1.146	0.351	0.072	0.034	0.083	0.035

* Statistically different from vehicle control by Dunnett’s test, α = 0.05.

g, grams; g/100 = grams per 100 grams of body weight; SD, standard deviation.

Figure 1.  Results of the SRBC antibody forming cell (AFC) assay for TCE. Exposure to TCE resulted in a slight decrease in the number of spleen cells that was without dose response and was not statistically significant (a). No effect on the AFC responses was noted for the 100 and 300 ppm groups, while the 1000 ppm group had a 71% and 64% decrease in the (b) AFC/spleen and (c) AFC/10⁶ splenocytes responses when compared to controls. The positive control CYP resulted in the expected decreases in spleen cell counts and AFC responses. Values represent the mean (± SE) of eight animals. * p < 0.05.

Table 3.  Terminal body weights and absolute and relative organ weights for animals exposed to PERC.

Concentration PERC (ppm)		Final body weight (g)	Kidney		Liver		Spleen		Thymus
			(g)	(g/100)	(g)	(g/100)	(g)	(g/100)	(g)	(g/100)
0	Mean	239.9	1.666	0.697	6.832	2.847	0.506	0.211	0.427	0.176
	SD	17.5	0.156	0.074	0.631	0.139	0.088	0.029	0.144	0.050
100	Mean	232.8	1.600	0.687	6.821	2.927	0.494	0.212	0.377	0.161
	SD	9.2	0.155	0.062	0.563	0.172	0.060	0.021	0.103	0.039
300	Mean	230.1	1.581	0.688	7.067	3.070*	0.474	0.206	0.388	0.169
	SD	12.8	0.078	0.027	0.502	0.092	0.076	0.029	0.048	0.019
1000	Mean	222.6	1.586	0.715	6.978	3.131*	0.464	0.209	0.358	0.162
	SD	14.8	0.142	0.076	0.803	0.243	0.056	0.025	0.081	0.041

* Statistically different from vehicle control by Dunnett’s test, α = 0.05.

g, grams; g/100, grams per 100 grams of body weight; SD, standard deviation.

Figure 2.  Phagocytic activity of pulmonary alveolar macrophages (PAM) following PERC exposure. Exposure to PERC did not result in any alterations in ability of PAM to phagocytize fluorescent bead(s) when compared to controls. The wide un-shaded (white) bars represent the total percentage of PAM containing any number of beads; the counts were further stratified into those containing 1–4 beads (black bars) and those containing ≥ 5 beads (grey bars) to further assess any reduction in activity. Values represent the mean (± SD) from cells of eight animals.

Figure 3.  Results of the SRBC antibody forming cell (AFC) assay for PERC. Exposure to PERC did not result in a treatment-related effect on the (a) number of spleen cells or (b and c) AFC responses. The positive control CYP resulted in the expected decreases in spleen cell counts and AFC responses. Values represent the mean (± SE) of eight animals. * p < 0.05.