De Ryck L M, Raus J C
Endocrinology. 1983 Jul;113(1):399-408. doi: 10.1210/endo-113-1-399.
Slices of normal mammary tissue from pregnant and lactating mice and slices of neoplastic (MXT) mouse mammary tissue were superfused with estradiol (E2) and estrone (E1) each labeled with a different isotope. Isotope concentrations in tissue and perfusate at the steady state were used to calculate fractions and rates of uptake, metabolism and release of estrogens by the tissue perfused. Both E2 and E1 entered equally well and were concentrated to the same extent by normal and neoplastic mammary tissue. However, much smaller tissue to medium ratios and larger diffusible fractions of estrogens were found in tumor slices as compared to mammary tissue from both pregnant and lactating mice, the uptake being the highest in pregnancy mammary glands. The interconversion between E1 and E2 was found to favor the formation of E2 in normal mammary tissue, the metabolic activity being the highest in lactating glands. In the MXT tumor slices the conversion of E1 into E2 was predominant as well but in contrast to the almost negligible metabolism of E2 in normal mammary tissue, a large fraction of E2 was converted into E1. The observed differences in estrogen uptake and metabolism between pregnant and lactating mammary glands were in concordance with the functional characteristics of the tissues. Furthermore, E1 was shown to play an important role in the mouse mammary gland as a metabolic precursor of E2. A different metabolic pattern was found in neoplastic mammary tissue.
将来自怀孕和哺乳期小鼠的正常乳腺组织切片以及肿瘤性（MXT）小鼠乳腺组织切片，分别用两种标记有不同同位素的雌二醇（E2）和雌酮（E1）进行灌流。利用稳态下组织和灌流液中的同位素浓度，计算灌流组织对雌激素的摄取、代谢和释放的分数及速率。E2和E1进入正常和肿瘤性乳腺组织的情况相同，且在相同程度上被浓缩。然而，与来自怀孕和哺乳期小鼠的乳腺组织相比，肿瘤切片中雌激素的组织与介质比值更小，可扩散分数更大，摄取量在怀孕乳腺中最高。发现正常乳腺组织中E1和E2之间的相互转化有利于E2的形成，代谢活性在哺乳期腺体中最高。在MXT肿瘤切片中，E1向E2的转化也占主导，但与正常乳腺组织中E2几乎可忽略不计的代谢情况相反，很大一部分E2转化为了E1。怀孕和哺乳期乳腺之间观察到的雌激素摄取和代谢差异与组织的功能特征一致。此外，E1在小鼠乳腺中作为E2的代谢前体发挥着重要作用。在肿瘤性乳腺组织中发现了不同的代谢模式。
