Protective role of medroxyprogesterone acetate on N-methyl-N-nitrosourea-induced lymphomas in BALB/c female mice.
In a previous paper we reported the occurrence of a high incidence of lymphomas in N-methyl-N-nitrosourea (MNU)-treated mice, in the course of an experiment of combined chemical-hormonal carcinogenesis in mammary gland, in which we used medroxyprogesterone acetate (MPA) and MNU in different treatment protocols. In this report we have analyzed the action of MPA in the leukemogenic effects of MNU, by specifically selecting for the analysis experimental groups in which only few mammary carcinomas had developed. A high incidence of lymphomas (65%, median latency: 176 days) was registered in MNU-treated mice, and the administration of MPA was associated with a significant reduction in the incidence of lymphomas (P<0.001) in all protocols.
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Laboratory of Hormonal Carcinogenesis, Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina.
Lanari
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C
Molinolo
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D000818:Animals; D005260:Female; D007150:Immunohistochemistry; D015994:Incidence; D008223:Lymphoma / Q000139:chemically induced / Q000517:prevention & control*; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology*; D008770:Methylnitrosourea / Q000633:toxicity*; D051379:Mice; D008807:Mice, Inbred BALB C
D008770:Methylnitrosourea; D017258:Medroxyprogesterone Acetate