Quantitative Studies of Tissue Uptake and Disposition of Hormones

A two-tracer continuous flow perfusion experimental design has been used to measure the entry of steroids (oestradiol, oestrone, progesterone, 20α-dihydroprogesterone, testosterone, androstenedione, cortisol, cortisone) and nucleic acid precursors (uridine, cytidine, UMP) into several tissues, using slices (human endometrium, endometrial adenocarcinoma, placenta, foetal membranes, rat and rabbit liver) or cell suspensions (chorion, amnion, liver, choriocarcinoma Be/Wo). Rates of interconversion between the perfused compounds and rates of release into the medium were also measured. The response of the system to additions of hormones, drugs and plasma proteins was evaluated by measuring rates and concentrations. The entry of oestrogen sulphates and UMP into tissues was compared with the entry of the corresponding unesterified compounds.