Abstract
Our understanding of the intracrine (or local) regulation of estrogen and other steroid synthesis and degradation expanded in the last decades, also thanks to recent technological advances in chromatography mass-spectrometry. Estrogen responsive tissues and organs are not passive receivers of the pool of steroids present in the blood but they can actively modify the intra-tissue steroid concentrations. This allows fine-tuning the exposure of responsive tissues and organs to estrogens and other steroids in order to best respond to the physiological needs of each specific organ. Deviations in such intracrine control can lead to unbalanced steroid hormone exposure and disturbances. Through a systematic bibliographic search on the expression of the intracrine enzymes in various tissues, this review gives an up-to-date view of the intracrine estrogen metabolisms, and to a lesser extent that of progestogens and androgens, in the lower female genital tract, including the physiological control of endometrial functions, receptivity, menopausal status and related pathological conditions. An overview of the intracrine regulation in extra gynecological tissues such as the lungs, gastrointestinal tract, brain, colon and bone is given. Current therapeutic approaches aimed at interfering with these metabolisms and future perspectives are discussed.
Highlights
The term “intracrinology,” coined in 1988 by prof Labrie, refers to the ability of peripheral tissues to use blood precursors and generate steroids (Labrie, 1991)
This review summarizes our knowledge of intracrinology in peripheral tissues like the endometrium, lungs, gastrointestinal tract (GIT), bone and central nervous system (CNS), with special attention to the metabolism of estrogens
Studies retrieved by the systematic search demonstrated that most investigations rely on RT-PCR or IHC to detect enzyme and protein, and frequently without multiple-technique confirmation of the data
Summary
The term “intracrinology,” coined in 1988 by prof Labrie, refers to the ability of peripheral tissues to use blood precursors and generate steroids (Labrie, 1991). A novel SRD, DHRS11, was shown to possess in vitro 17-keto to 17β-hydroxyl reductive action (able to use E1, 5 or 4 androstenes, androstanes), plus reductive 3βHSD activity toward 4 pregnenes and other compounds (5β-steroids, bile acids; Table 2 and Figure 2; Endo et al, 2016). Accessed on date: February 2018); 2Isomer 5α-pregnan-3β,17α-diol-20-one exists They are most likely produced by SULT2A1 (active on 3α-hydroxy bile acids) (Strott, 2002; Rižner, 2016) but no 3α-stereo specific sulphatase is known to date. Even in the absence of the enzymatic machinery to metabolize cholesterol (StAR, steroidogenic factor, CYP17A1 and CYP11A1), DHEA, P5 and especially their sulphated-conjugates have high blood concentrations (Table 1), and are used to generate all other steroids in peripheral tissues. This old-and-proven steroidal chemistry based approach is used even in modern era
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
