Birgit Svenstrup

Reduced androgen levels in adult Turner syndrome: influence of female sex steroids and growth hormone status

In girls with Turner syndrome androgen levels are reduced. In order to assess androgen status in women with Turner syndrome, we compared untreated adult women with Turner syndrome with a group of normal women. In addition, the effects of female sex hormone replacement therapy and GH status on the levels of circulating androgens in Turner syndrome was examined.

Serum steroid levels in intact and endocrine ablated BALB/C nude mice and their intact littermates

An investigation was made of the serum steroid levels found in intact and endocrine ablated nude mice of both sexes and in their intact homozygous littermates. The results showed that nude mice have a normal steroidogenesis, but with decreased levels of circulating steroids compared to those of the littermates. The efficacy of the endocrine ablations was confirmed by the reduction in serum oestrone following oophorectomy, and by the reduction in serum testosterone and progesterone following orchiectomy. The normal steroidogenesis in nude mice, and the similarities between mouse and man with regard to changes in serum steroids following oophorectomy and orchiectomy, support the usefulness of human tumor xenograft models for the study of hormone-tumor interactions.

Comparison of the effect of cortisol on aromatase activity and androgen metabolism in two human fibroblast cell lines derived from the same individual

The effect of preincubation with cortisol on estrogen and androgen metabolism was investigated in human fibroblast monolayers grown from biopsies of genital and non-genital skin of the same person. The activity in the cells of aromatase, 5 alpha-reductase, 17 beta-hydroxysteroid oxidoreductase and 3 alpha-hydroxysteroid oxidoreductase was investigated by isolating estrone, estradiol, estriol, dihydrotestosterone, androstanedione, androsterone, 3 alpha-androstanediol, testosterone and androstenedione after incubation of the cells with [14C]testosterone or [14C]androstenedione. For experiments with 14C-labeled substrate the cells were incubated in medium, charcoal stripped of steroids without Phenol Red. Preincubation from 6 to 36 h with cortisol in concentrations of 10(-8) - 10(-6) M showed maximal stimulation of aromatase activity after 12 h preincubation with cortisol in concentrations of 0.5-1.0 x 10(-6) M in both cell lines. When preincubation with cortisol was omitted no estrogen synthesis was detected. The formation of androgen was not altered after preincubation with cortisol. Pronounced differences were found in estrogen and in androgen metabolism in the two cell lines suggesting a local regulation of the hormonal environment. The aromatase activity, which is low in many tissues could be stimulated by cortisol without altering the androgen metabolism was found to be a suitable system for investigations of the cellular interconversion of androgens and estrogens and for investigations of the in vitro regulation of the enzymes involved.

Dehydroepiandrosterone supplementation in women with adrenal failure: impact on twenty‐four hour GH secretion and IGF‐related parameters

objective  In women, GH secretion is strongly influenced by oestrogen status, whereas the role of androgens is unclear. We, therefore, examined GH secretory dynamics during low vs. normalized androgen levels in women with adrenal failure.

Steroid metabolism in the hormone dependent MCF-7 human breast carcinoma cell line and its two hormone resistant subpopulations MCF-7/LCC1 and MCF-7/LCC2

Androgen and estrogen metabolism was investigated in the hormone-dependent human breast cancer cell line MCF-7 and its two hormone-resistant sublines MCF-7/LCC1 and MCF-7/LCC2. Using the product isolation method, the activity of aromatase, 5alpha-reductase, 3alpha/beta-hydroxysteroid oxidoreductase and 17beta-hydroxysteroid oxidoreductase were investigated isolating the following steroids: estriol (E3), estradiol (E2), estrone (E1), 3alpha/beta-androstanediol (A-diol), testosterone (T), dihydrotestosterone (DHT), androsterone (AND), androstenedion (4-AD) and androstanedione (A-dion). For all experiments, cells were preincubated with cortisol and subsequently incubated with [14C]T or [14C]4-AD as the substrate in medium without phenol red and with serum charcoal stripped of steroids. The results showed no aromatase activity in any of the cell lines under the experimental conditions used, and preincubation with cortisol had no effect on the enzyme activity. With [14C]T as the substrate, the metabolized level of DHT was very similar in the three cell lines, though MCF-7/LCC1 and MCF-7/LCC2 utilized the substrate to a much lesser extent. The amount of DHT and 4-AD produced were comparable in the two hormone-resistant cell lines, while the amount of 4-AD was significantly higher in MCF-7 cells. No differences in enzyme activity were found in the three cell lines when [14C]4-AD was used as the substrate. This study showed an altered androgen metabolism in the MCF-7/LCC1 and MCF-7/LCC2 sublines compared to the parent MCF-7. However, since treatment with DHT and T inhibited cell growth equally well in all three tumor cell lines, it is unlikely that the found differences in steroid metabolism was involved in the acquisition of the endocrine resistance of the two MCF-7 sublines.

Estrogen- and progesterone receptors in normal cycling endometrium as studied by end-point titration

A thorough knowledge of the normal physiological fluctuations in estrogen-(ER) and progesterone receptors (PgR) is essential to characterize the changes in ER and PgR in the abnormal endometrium. We investigated the distribution of ER and PgR in frozen human cycling endometrial tissue using the commercially available ER-and PgR-ICA kits. Two-fold end-point titration (EPT) of ER and PgR antibodies was implemented to semi-quantitate more accurately ER and PgR. Semiquantitation of ER and PgR using EPT was significantly correlated to results obtained using either simple scoring or enzyme-immunoassay (EIA) methods. ER and PgR staining fluctuated in relation to the menstrual cycle. In most subphases PgR exceeded ER in both epithelial and stromal cells. Highest levels of ER and PgR were demonstrated in the glands of the functionalis in mid-to-late proliferative phases, whereas both receptors were almost undetectable by immunohistology in the glands of mid-to-late secretory phases. Endometrial stromal cells had high and nearly constant EPT values for PgR, but low values for ER througout the menstrual cycle. EPT values for ER and PgR were generally higher in the basalis than in the functionalis but showed similar cyclic fluctuations. Our results further substantiate the view that the response to hormonal stimulation is cell-type specific, and suggest differences in steroid metabolism according to cell type and layer.

Morning versus evening administration of estradiol to girls with turner syndrome receiving growth hormone: impact on growth hormone and metabolism. A randomized placebo-controlled crossover study.

Timing of 17β‐estradiol (E2) administration in relation to that of GH could influence the “first pass effect” of E2 on hepatic IGF‐I secretion. In order to test this hypothesis, a randomized double‐blind placebo‐controlled crossover study was conducted. Nine Turner girls (12.8–20.0 y) were treated for 2 mo periods with GH 0.1 IU/kg/d sc at bedtime, and oral E2 6–11 μg/kg/d in the morning and placebo in the evening in one 2‐mo period and vice versa in the other period. After each period, 24‐h blood sampling was performed. IGF‐I and mean 24‐h integrated GH were comparable. However, the IGF‐I/IGFBP‐3 ratio was higher (p= 0.05) and insulin levels were lower after evening administration of E2 (24 h: p= 0.03). During an oral glucose tolerance test in the morning, glucagon and insulin were lower following evening E2 administration (ANOVA: glucagon, p= 0.03; insulin, p= 0.04), as well as insulin resistance tended to be lower (p= 0.09).

Circulating sex hormones and gene expression of subcutaneous adipose tissue oestrogen and alpha-adrenergic receptors in HIV-lipodystrophy: implications for fat distribution

Objective  Circulating oestradiol and testosterone, which have been shown to increase in human immunodeficiency virus (HIV)‐infected patients following highly active antiretroviral therapy (HAART), may influence fat distribution and insulin sensitivity. Oestradiol increases subcutaneous adipose tissue in humans possibly through binding to oestrogen‐receptor‐α, which in turn activates anti‐lipolytic α2A‐adrenergic‐receptor.

N-Acetyllactosamine and sialosyl-N- acetyllactosamine in normal and malignant human endometrium

We have evaluated using immunohistochemistry the expression of the type 2 chain histo-blood group precursorsN-acetyllactosamine (Lac), sialosyl-Lac (S-Lac) and binary-sialosyl Lac (DS-Lac) in epithelial cells of normal non-secretory, gestational and malignant human endometrial tissues (n=120). Staining was assessed in relation to genetic (ABO, Lewis blood group and secretor status), morphologic and hormonal factors (serum levels of estrogens). The staining pattern for Lac, S-Lac and DS-Lac showed great variation and was not related to blood group or the secretor status. Staining for Lac showed a limited distribution in both normal and malignant endometrium and was most frequenly found in gestational and atrophic endometrium. S-Lac was strongly expressed, but only infrequently as DS-Lac structures in normal endometrium. Staining for both S-Lac and DS-Lac was most widespread in proliferating endometria. Endometrial carcinomas showed an increased staining for DS-Lac and a varied, and in most cases a reduced, staining for S-Lac, a pattern like that previously found in secretory endometrium. Staining scores for S-Lac showed a weak correlation with serum levels of free estradiol. Thus, the increased expression of DS-Lac in contrast to S-Lac structures in endometrial carcinomas is probably unrelated to both hormonal and genetic factors and may be considered a ‘tumor-associated’ but not a tumor-specific change in endometrial cell glycosylation.

Blood group A/B-defined glycosyltransferase and A/B blood group antigens in human normal and malignant endometrium in relation to morphology, age and oestrogen levels

We have used monoclonal antibodies to study the expression and regulation of A/B antigens and A/B transferase in normal and malignant human endometrium by immunohistochemistry. Staining was evaluated against blood group status, morphology, age ad serum oestrogen levels. The expression of the antigens, in contrast tothe expression of the transferase, was related to the A subtype (A1/A2) and the ABH secretor status. Normal, non-secretory endometria and most well-differentiated endometrial carcinomas from ABH secretors expressed the antigens and the transferase, but showed a morphology-dependent variation in the expression and degree of coexpression. n contrast, most grade 2 and 3 carcinomas were found to lack both structures, whereas secretory endometrium had a high expression of the transferase but expressed the antigens on only a few cells. The transferase expression was correlated inversely with age and positively with the level of free oestradiol in serum. Our findings suggest that A/B antigenic expression in the endometrium may be regulated at different levels — at the A/B transferase level and at a precursor substrate lvel — and that both genetic and hormonal factors are probably involved in the regulatory process.