Colorectal carcinoma in a rat model: suppression of tumour development and altered host immune status following treatment with anti B-lymphocyte serum.
The rate of colonic tumour development and immune capability in rats whose B-lymphocyte function was suppressed by injections of rabbit anti-rat IgM and also given the carcinogen dimethylhydrazine (DMH) were studied. Four rat groups were arranged to receive either DMH + anti-IgM, DMH + normal rabbit serum (NRS), saline + anti-IgM, or saline + NRS. Tumour weight, blood and mesenteric lymph node B-lymphocyte numbers, in vivo allograft response, in vitro lymphocytotoxicity, and leucocyte migration inhibition response (LMI) were recorded fortnightly. Tumour induction was delayed in the DMH + anti-IgM (treated tumour) group, which developed less tumour than the DMH + NRS (untreated tumour) group (p less than 0.001). Spleen cell lymphocytotoxicities were depressed in treated rats when compared to either the saline + anti-IgM (treated control) rats or the untreated rats (P less than 0.02), whereas anti-IgM treatment suppressed lymphocytotoxicity responses in control rats (p less than 0.05). The untreated tumour rats were tumour immune by LMI; however, the treated tumour rats did not express this in vitro tumour immunity. The B-lymphocyte levels in the mesenteric lymph nodes of untreated tumour rats increased with tumour induction (p less than 0.05), whereas in the treated tumour rats B-lymphocyte levels were not similarly stimulated.
D000818:Animals; D000961:Antilymphocyte Serum / Q000627:therapeutic use*; D001402:B-Lymphocytes / Q000276:immunology*; D001835:Body Weight; D002464:Cell Migration Inhibition; D003110:Colonic Neoplasms / Q000276:immunology / Q000628:therapy*; D007958:Leukocyte Count; D007962:Leukocytes / Q000276:immunology; D008198:Lymph Nodes / Q000637:transplantation; D008297:Male; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains; D012004:Rectal Neoplasms / Q000276:immunology / Q000628:therapy*; D013154:Spleen / Q000637:transplantation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014184:Transplantation, Homologous
D000961:Antilymphocyte Serum