LOU/C

Genotype:

Pigmentation genes: aa BB cc hh PP RR

Mhc: RT1^u(RT1.A^uB/D^uC^u)

Erythrocyte antigens:RT2 ^b RT8 ^b

Lymphocyte antigens:RT6 ^b RT7 ^a

Inbr. Gen.: At Ztm (1998), F50.

Origin: Bazin and Beckers, 1970, from rats of presumed Wistar origin kept at the Universite Catholique de Louvain. LOU/C was selected from among 28 parallel lines for its high incidence of plasmacytomas. Histocompatible with LOU/M (6, 9). To Max, to Ztm in 1994.

Reproduction: Good reproductive performance. At Ztm, 0.93 young weaned/female/week, and on average 7,0 young weaned per litter.

Tumours (Spontaneous): About 32% of males and 14% of females over 8 months of age develop sponta-neous plasmacytomas, usually in the ileocecal lymph nodes. Tumours develop rapidly and can be detected by palpation (2). Surgical removal of ileocecal lymph nodes decreases plasmacytoma incidence to less than 2%, suggesting that cells in the ileo-cecal nodes undergo malignant transformation first (12). Ultrastructure of tumours described by Burtonboy et al. (11). About 60% of plasmacytomas synthesize mono-clonal immunoglobulins, including Bence-Jones proteins and immunoglobulins IgA, IgD, IgE, IgG1, IgG2a, IgG2b, IgG2c, and IgM (1-5, 7). Tumours are transplantable in solid or ascites form, and retain their secretory properties through successive passages (1, 5, 9). Allotypes of kappa and alpha chain loci described by Beckers et al. (8). Amino acid sequence of a kappa Bence Jones protein described by Starace and Querinjean (13). More than 800 transplantable immunocytomas are now available.

Other characteristics: Genetic marker profile described by Bender et al. (1994) (10).

References:

1. Bazin, H., C. Deckers, A. Beckers, and J. F. Heremans. 1972. Brief communication: Trans-plantable immunoglobulin-secreting tumours in rats. I. General features of LOU/Wsl strain rat immunocytomas and their monoclonal proteins. Int. J. Cancer 10: 568 580.

2. Bazin, H., A. Beckers, C. Deckers, and M. Moriame. 1973. Brief communication: Transplantable immunoglobulin-secreting tumours in rats. V. Monoclonal immunoglobulins secreted by 250 ileocecal immunocytomas in LOU/Wsl rats. J. Natl. Cancer Inst. 51: 1359 1361.

3. Bazin, H. 1974. Tumeurs sécretant des immunoglobulines chez le rat LOU/Wsl. Étude portant sur 200 immunocytomes. Ann. Immunol. 125C: 277 279.

4. Bazin, H., A. Beckers, and P. Querinjean. 1974. Three classes and four (sub)classes of rat immunoglobulins: IgM, IgA, IgE and IgG1, IgG2a, IgG2b, IgG2c. Eur. J. Immunol. 4: 44 48.

5. Bazin, H., P. Querinjean, A. Beckers, J. F. Heremans, and F. Dessy. 1974. Transplantable immunoglobulin-secreting tumours in rats. IV. Sixty-three IgE-secreting immunocytoma tumours. Immunology 26: 713 723.

6. Bazin, H. 1977. Inbred strains. Rat News Lett. 1: 27.

7. Bazin, H., A. Beckers, G. Urbain-Vansanten, R. Pauwels, C. Bruyns, A. F. Tilkin, B. Platteau, and J. Urbain. 1978. Transplantable IgD immunoglobulin-secreting tumors in rat. J. Immunol. 121: 2077 2082.

8. Beckers, A., P. Querinjean, and H. Bazin. 1974. Allotypes of rat immunoglobulins-II. Distri-bution of the allotypes of kappa and alpha chain loci in different inbred strains of rats. Immunochemistry 11: 605 609.

9. Beckers, A. and H. Bazin. 1978. Incidence of spontaneous ileocecal immunocytomas in hybrids of LOU/C rats and rat strains with low spontaneous tumor incidence: Brief communication. J. Natl. Cancer Inst. 60: 1505 1508.

10. Bender, K., P. Balogh, M.F. Bertrand, M. den Bieman, O. van Deimling, S. Eghtessadi, G.A. Gutman, H. J. Hedrich, S.V. Kluge, K. Matsumoto, D.H. Moralejo, M. Nagel, A. Portal, C.-M. Prokop, R.T. Seibert and L.F.M. van Zutphen. 1994. Genetic characterization of inbred strains of the rat (Rattus norvegicus). I. Exp. Anim. Sci. 36: 151-166.

11. Burtonboy, G., A. Beckers, J. Rodhain, H. Bazin, and M. E. Lamy. 1978. Rat ileocecal immuno-cytoma. An ultrastructural study with special attention to the presence of viral particles. J. Natl. Cancer Inst. 61: 477 484.

12. Moriame, M., A. Beckers, and H. Bazin. 1977. Decrease in the incidence of malignant ileo-caecal immunocytome in LOU/C rats after surgical removal of the ileo-caecal lymph nodes. Cancer Lett. 3: 139 143.

13. Starace, V. and P. Querinjean. 1975. The primary structure of a rat k Bence Jones protein: Phylogenetic relationships of V- and C-region genes. J. Immunol. 115: 59 62.