Accumulation of tritiated oestradiol by human breast tissue

The uptake of oestradiol-17s by normal and neoplastic human breast tissue has been measured following administration of tritiated oestradiol-17s. Both tissues accumulate and retain oestradiol for up to 5 hours. Tumour tissue accumulates higher concentrations of oestradiol-17s than normal tissue. Dromostanolone propionate inhibits the uptake of oestradiol-17s by the tumour but has no apparent effect on the uptake by normal breast tissue.