Pilot study on the growth inhibition by estramustine phosphate (Estracyt) of rat mammary tumours sensitive and insensitive of oestrogen.
Rat mammary tumours induced by 7,12-dimethylbenz(a)anthracene had a higher concentration of 3H and 14C than muscle after injection of estramustine phosphate labelled with 3H in the oestrogen moiety and 14C in the alkylating moiety. Thin-layer chromatography showed that dephosphorylated estramustine phosphate was present in the tumours but no free oestradiol-17beta. The uptake of the drug in the tumours was parallelled by a dose dependant retardation of tumour growth and a prevention of tumour number increase. Estramustine phosphate also retarded growth of mammary tumours resistant to treatment with oestradiol-17 beta. It is concluded that estramustine phosphate has a greater effect on tumour growth than oestrogen.
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004961:Estramustine / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use*; D004967:Estrogens / Q000378:metabolism / Q000627:therapeutic use*; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy* / Q000378:metabolism; D009588:Nitrogen Mustard Compounds / Q000627:therapeutic use*; D010865:Pilot Projects; D051381:Rats
D004967:Estrogens; D009588:Nitrogen Mustard Compounds; D004961:Estramustine; D015127:9,10-Dimethyl-1,2-benzanthracene