Continued expression of anti-soy protein antibodies in rats bred on a soy protein–free diet for one generation: The importance of dietary control in oral sensitization research  Léon M. Knippels, MSca, b, André H. Penninks, PhDa, b, Geert F. Houben, PhDa  Journal of Allergy and Clinical Immunology  Volume 101, Issue 6, Pages 815-820 (June 1998) DOI: 10.1016/S0091-6749(98)70309-4 Copyright © 1998 Mosby, Inc. Terms and Conditions

Fig. 1 Soy protein–specific IgG antibody titers in BN rats bred and raised on soy protein–containing diet for several generations (RB) and after being fed soy protein–free diet for at least 6 months (F0). After at least 6 months on soy protein–free diet, F0 animals were used to start breeding. Four generations of offspring were bred and raised on soy protein–free diet (F1, F2, F3, and F4). Blood samples were taken from RB animals at arrival and at regular time intervals from F0, F2, F3, and F4 animals. Data are presented as 2log IgG titers ± SD of groups of at least four rats from every generation of offspring measured by ELISA with pooled serum from F3 animals as negative control. Journal of Allergy and Clinical Immunology 1998 101, 815-820DOI: (10.1016/S0091-6749(98)70309-4) Copyright © 1998 Mosby, Inc. Terms and Conditions

Fig. 2 A, Soy protein–specific IgG titers in young BN rats fed soy protein–containing diet for several generations (RB) and exposed ad libitum to SBIF (20 mg protein/ml) through drinking water continuously for 42 days and in young RB animals parenterally injected with SBIF (RB SBIF i.p.). Blood samples were obtained at weekly intervals in orally exposed RB animals and at day 28 in parenterally exposed RB animals. Data are presented as mean 2log IgG titers ± SD of four rats per group as determined by ELISA in blood samples with pooled serum from the third generation of offspring bred on soy protein–free diet as negative control. B, Soy protein–specific IgG titers in BN rats bred and raised on soy protein–free diet for four generations (F4) and young F4 animals parenterally injected with either SBIF (F4 SBIF i.p.) or USF (F4 USF i.p.) or exposed orally by administration of 20 mg protein/ml SBIF (F4 SBIF ad lib) or 20 mg protein/ml USF (F4 USF ad lib) ad libitum through drinking water continuously during 42 days. Soy protein–specific IgG titers were determined by ELISA in blood samples obtained at days 0, 28, and 42 by using pooled preserum as negative control. Data are presented as mean 2log IgG titers ± SD of four rats per group. Respective time points for specific antibody determination are indicated in the bars. No SDs are given for intraperitoneally sensitized animals because sera of individual animals were pooled. Statistical analysis was performed by two-tailed Student's t test comparison of prestudy antibody titers and antibody titers on oral exposure to soy proteins. *p < 0.05, **p < 0.01, ***p < 0.0001. Journal of Allergy and Clinical Immunology 1998 101, 815-820DOI: (10.1016/S0091-6749(98)70309-4) Copyright © 1998 Mosby, Inc. Terms and Conditions