Effect of cyclophosphamide on leukocytic subset distributions in rats carrying the Dunning R3327-MAT-LyLu prostatic adenocarcinoma.
The Dunning R3327 adenocarcinoma represents a model for studying prostate cancer in rats; early studies have indicated its utility for studying relationships between tumor growth, immunologic markers, and chemotherapy. Normal animals and those bearing the metastatic Dunning R3327 MAT-LyLu tumor were treated with 10, 30, and 100 mg/kg doses of cyclophosphamide (CTX) and their spleens assayed for leukocytic subset distributions using monoclonal antibodies. Tumor-bearing animals had significant reductions in helper T cell content as well as reduced helper/suppressor T cell ratios, compared to controls. These effects occurred rapidly following implantation and were not reversed by chemotherapy. When administered to both tumor- and non-tumor-bearing animals, CTX also depleted T cell populations. Despite reductions produced in all subsets, two administrations of CTX (30 mg/kg) were capable of retaining (in non-tumor-bearing animals) or restoring (in tumor-bearing) normal helper/suppressor T cell ratios. Such studies aid in identifying therapeutically effective dosages of cytotoxic drugs that minimize their deleterious effects on the immune system.
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal; D002460:Cell Line; D003520:Cyclophosphamide / Q000627:therapeutic use*; D007962:Leukocytes / Q000145:classification*; D008297:Male; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000276:immunology; D051381:Rats; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D000911:Antibodies, Monoclonal; D003520:Cyclophosphamide