Analysis of information sources in references of the Wikipedia article "Norethisterone" in English language version.
Norethisterone and its acetate and enanthate esters are progestogens that have weak estrogenic and androgenic properties.
Norethisterone binds to SHBG with less affinity than endogenous androgens and oestrogens [...]
Many synthetic steroids with high myotrophic activity exhibit myotrophic–androgenic dissociation, since, due to changes introduced in the structure of ring A, they will probably not be substrates for the 5α-reductases [85]. 5α-Reduction does not always amplify the androgenic potency in spite of high RBA of androgens to the AR. This is the case for norethisterone (Fig. 1, 34), a synthetic 19-nor-17α-ethynyl testosterone derivative, which also undergoes enzyme-mediated 5α-reduction and exerts potent androgenic effects in target organs. 5α-Reduced norethisterone displays a higher AR binding but shows a significantly lower androgenic potency than unchanged norethisterone [102,103].
{{cite book}}: |journal= ignored (help)[...] several mono- and disulphated as well as mono- and diglucuronidated metabolites of NET have been detected in urine from NET treated women [16,17]. In unconjugated form these NET (or MeNET) metabolites are represented by 5α- and 5β-reduced NET (5α-NET or 5β-NET) and by 3α- and 3β-hydrogenated 5α-NET and 5β-NET, leading to 3α,5α-NET, 3β,5α-NET, 3α,5β-NET and 3β,5β-NET or their corresponding MeNET metabolites (Figs. 1 and 2). These steroid conversions of NET or MeNET may take place in the liver, but also in the pituitary, endometrium, prostate, vagina and breast. The enzymes involved in these metabolic processes are 5α- and 5β-reductase as well as 3α- and 3β-hydroxysteroid dehydrogenase (HSD).
Similar androgenic potential is inherent to norethisterone and its prodrugs (norethisterone acetate, ethynodiol diacetate, lynestrenol, norethynodrel, quingestanol [acetate]).
Many synthetic steroids with high myotrophic activity exhibit myotrophic–androgenic dissociation, since, due to changes introduced in the structure of ring A, they will probably not be substrates for the 5α-reductases [85]. 5α-Reduction does not always amplify the androgenic potency in spite of high RBA of androgens to the AR. This is the case for norethisterone (Fig. 1, 34), a synthetic 19-nor-17α-ethynyl testosterone derivative, which also undergoes enzyme-mediated 5α-reduction and exerts potent androgenic effects in target organs. 5α-Reduced norethisterone displays a higher AR binding but shows a significantly lower androgenic potency than unchanged norethisterone [102,103].
[...] several mono- and disulphated as well as mono- and diglucuronidated metabolites of NET have been detected in urine from NET treated women [16,17]. In unconjugated form these NET (or MeNET) metabolites are represented by 5α- and 5β-reduced NET (5α-NET or 5β-NET) and by 3α- and 3β-hydrogenated 5α-NET and 5β-NET, leading to 3α,5α-NET, 3β,5α-NET, 3α,5β-NET and 3β,5β-NET or their corresponding MeNET metabolites (Figs. 1 and 2). These steroid conversions of NET or MeNET may take place in the liver, but also in the pituitary, endometrium, prostate, vagina and breast. The enzymes involved in these metabolic processes are 5α- and 5β-reductase as well as 3α- and 3β-hydroxysteroid dehydrogenase (HSD).
Similar androgenic potential is inherent to norethisterone and its prodrugs (norethisterone acetate, ethynodiol diacetate, lynestrenol, norethynodrel, quingestanol [acetate]).
Many synthetic steroids with high myotrophic activity exhibit myotrophic–androgenic dissociation, since, due to changes introduced in the structure of ring A, they will probably not be substrates for the 5α-reductases [85]. 5α-Reduction does not always amplify the androgenic potency in spite of high RBA of androgens to the AR. This is the case for norethisterone (Fig. 1, 34), a synthetic 19-nor-17α-ethynyl testosterone derivative, which also undergoes enzyme-mediated 5α-reduction and exerts potent androgenic effects in target organs. 5α-Reduced norethisterone displays a higher AR binding but shows a significantly lower androgenic potency than unchanged norethisterone [102,103].
[...] several mono- and disulphated as well as mono- and diglucuronidated metabolites of NET have been detected in urine from NET treated women [16,17]. In unconjugated form these NET (or MeNET) metabolites are represented by 5α- and 5β-reduced NET (5α-NET or 5β-NET) and by 3α- and 3β-hydrogenated 5α-NET and 5β-NET, leading to 3α,5α-NET, 3β,5α-NET, 3α,5β-NET and 3β,5β-NET or their corresponding MeNET metabolites (Figs. 1 and 2). These steroid conversions of NET or MeNET may take place in the liver, but also in the pituitary, endometrium, prostate, vagina and breast. The enzymes involved in these metabolic processes are 5α- and 5β-reductase as well as 3α- and 3β-hydroxysteroid dehydrogenase (HSD).
Norethisterone and its acetate and enanthate esters are progestogens that have weak estrogenic and androgenic properties.