The impact of 17α-ethinylestradiol on roach (Rutilus rutilus) growth

17α-ethinylestradiol (EE2), found in pharmaceuticals is regularly consumed and secreted mainly from women. Consequently, a significant level of this endocrine disrupting chemical is cont inuously discharged into the aquatic environment. EE2 is the most potent known estrogen discharged, it can bioaccumulate in animals and persist in nature relatively long. Laboratory research indicates decreased population growth in fish exposed to EE2 and this may consequently change the time of fecundity, bias the sex ratio and decrease the survival rate in young fish. In this laboratory experiment the growth (length and weight) of roach was analyzed. Roach was exposed to different concentrations of EE2 (0 ng/l (control), 0.5 ng/l, 5.0 ng/l and 50.0 ng/l) for 75 days in their egg, larvae and juvenile phase. In the final result the mortality was higher among the estrogen treated roach. The weight and length was significantly increased among the estrogen treated roach (50.0 ng/l), but the condition factor was higher for the control. The high growth rate indicates a physiological response caused by the higher food supply among EE2 treated roach. The high mortality among the smallest EE2 treated roach probably influenced the final composition of EE2 treated roach, which were significantly larger. This is enhanced by the lower condition factor among the estrogen treated roach, which may indicate a depressed health due to EE2

Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone

Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading. We therefore investigated Wnt16 expression in the context of ageing, mechanical loading and unloading, estrogen deficiency and replacement, and estrogen receptor α (ERα) depletion. Quantitative real time PCR showed that Wnt16 mRNA expression was lower in cortical bone and marrow of aged compared to young female mice. Neither increased nor decreased (by disuse) mechanical loading altered Wnt16 expression in young female mice, although Wnt16 expression was decreased following ovariectomy. Both 17β-estradiol and the Selective Estrogen Receptor Modulator Tamoxifen increased Wnt16 expression relative to ovariectomy. Wnt16 and ERβ expression were increased in female ERα-/- mice when compared to Wild Type. We also addressed potential effects of gender on Wnt16 expression and while the expression was lower in the cortical bone of aged males as in females, it was higher in male bone marrow of aged mice compared to young. In the kidney, which we used as a non-bone reference tissue, Wnt16 expression was unaffected by age in either males or females. In summary, age, and its associated bone loss, is associated with low levels of Wnt16 expression whereas bone loss associated with disuse has no effect on Wnt16 expression. In the artificially loaded mouse tibia we observed no loading-related up-regulation of Wnt16 expression but provide evidence that its expression is influenced by estrogen receptor signaling. These findings suggest that while Wnt16 is not an obligatory contributor to regulation of bone mass per se, it potentially plays a role in influencing pathways associated with regulation of bone mass during ageing and estrogen withdrawal

Dehydroepiandrosterone Supplementation Results in Varying Tissue-specific Levels of Dihydrotestosterone in Male Mice

Dehydroepiandrosterone (DHEA), an adrenal androgen precursor, can be metabolized in target tissues into active sex steroids. It has been proposed that DHEA supplementation might result in restoration of physiological local sex steroid levels, but knowledge on the effect of DHEA treatment on local sex steroid levels in multiple tissues is lacking. To determine the effects of DHEA on tissue-specific levels of sex steroids, we treated orchiectomized (ORX) male mice with DHEA for 3 weeks and compared them with vehicle-treated ORX mice and gonadal intact mice. Intra-tissue levels of sex steroids were analyzed in reproductive organs (seminal vesicles, prostate, m. levator ani), major body compartments (white adipose tissue, skeletal muscle, and brain), adrenals, liver, and serum using a sensitive and validated gas chromatography-mass spectrometry method. DHEA treatment restored levels of both testosterone (T) and dihydrotestosterone (DHT) to approximately physiological levels in male reproductive organs. In contrast, this treatment did not increase DHT levels in skeletal muscle or brain. In the liver, DHEA treatment substantially increased levels of T (at least 4-fold) and DHT (+536%, P < 0.01) compared with vehicle-treated ORX mice. In conclusion, we provide a comprehensive map of the effect of DHEA treatment on intra-tissue sex steroid levels in ORX mice with a restoration of physiological levels of androgens in male reproductive organs while DHT levels were not restored in the skeletal muscle or brain. This, and the unexpected supraphysiological androgen levels in the liver, may be a cause for concern considering the uncontrolled use of DHEA

Comprehensive sex steroid profiling in multiple tissues reveals novel insights in sex steroid distribution in male mice

A comprehensive atlas of sex steroid distribution in multiple tissues is currently lacking, and how circulating and tissue sex steroid levels correlate remains unknown. Here, we adapted and validated a gas chromatography tandem mass spectrometry method for simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), androstenedione, progesterone (Prog), estradiol, and estrone in mouse tissues. We then mapped the sex steroid pattern in 10 different endocrine, reproductive, and major body compartment tissues and serum of gonadal intact and orchiectomized (ORX) male mice. In gonadal intact males, high levels of DHT were observed in reproductive tissues, but also in white adipose tissue (WAT). A major part of the total body reservoir of androgens (T and DHT) and Prog was found in WAT. Serum levels of androgens and Prog were strongly correlated with corresponding levels in the brain while only modestly correlated with corresponding levels in WAT. After orchiectomy, the levels of the active androgens T and DHT decreased markedly while Prog levels in male reproductive tissues increased slightly. In ORX mice, Prog was by far the most abundant sex steroid, and, again, WAT constituted the major reservoir of Prog in the body. In conclusion, we present a comprehensive atlas of tissue and serum concentrations of sex hormones in male mice, revealing novel insights in sex steroid distribution. Brain sex steroid levels are well reflected by serum levels and WAT constitutes a large reservoir of sex steroids in male mice. In addition, Prog is the most abundant sex hormone in ORX mice

Reduced Bone Mass and Muscle Strength in Male 5α-Reductase Type 1 Inactivated Mice

Androgens are important regulators of bone mass but the relative importance of testosterone (T) versus dihydrotestosterone (DHT) for the activation of the androgen receptor (AR) in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2), encoded by separate genes (Srd5a1 and Srd5a2). 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1−/− mice. Four-month-old male Srd5a1−/− mice had reduced trabecular bone mineral density (−36%, p<0.05) and cortical bone mineral content (−15%, p<0.05) but unchanged serum androgen levels compared with wild type (WT) mice. The cortical bone dimensions were reduced in the male Srd5a1−/− mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05) in orchidectomized WT mice but not in orchidectomized Srd5a1−/− mice. Male Srd5a1−/− mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05). Female Srd5a1−/− mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1−/− mice, is an indirect effect mediated by elevated circulating androgen levels

SERMs have substance specific effects on bone and these effects are mediated via ERαAF-1 in female mice

The bone-sparing effect of estrogens is mediated primarily via estrogen receptor (ER)α, which stimulates gene transcription through activation function (AF)-1 and AF-2. The role of ERαAF-1 for the estradiol (E(2)) effects is tissue specific. The selective ER modulators (SERMs) raloxifene (Ral), lasofoxifene (Las), and bazedoxifene (Bza) can be used to treat postmenopausal osteoporosis. They all reduce the risk for vertebral fractures, whereas Las and partly Bza, but not Ral, reduce the risk for nonvertebral fractures. Here, we have compared the tissue specificity of Ral, Las, and Bza and evaluated the role of ERαAF-1 for the effects of these SERMs, with an emphasis on bone parameters. We treated ovariectomized (OVX) wild-type (WT) mice and OVX mice lacking ERαAF-1 (ERαAF-1(0)) with E(2), Ral, Las, or Bza. All three SERMs increased trabecular bone mass in the axial skeleton. In the appendicular skeleton, only Las increased the trabecular bone volume/tissue volume and trabecular number, whereas both Ral and Las increased the cortical bone thickness and strength. However, Ral also increased cortical porosity. The three SERMs had only a minor effect on uterine weight. Notably, all evaluated effects of these SERMs were absent in ovx ERαAF-1(0) mice. In conclusion, all SERMs had similar effects on axial bone mass. However, the SERMs had slightly different effects on the appendicular skeleton since only Las increased the trabecular bone mass and only Ral increased the cortical porosity. Importantly, all SERM effects require a functional ERαAF-1 in female mice. These results could lead to development of more specific treatments for osteoporosis

The role of activation functions 1 and 2 of estrogen receptor-α for the effects of estradiol and selective estrogen receptor modulators in male mice

Estradiol (E2) is important for male skeletal health and the effect of E2 is mediated via estrogen receptor (ER)-α. This was demonstrated by the findings that men with an inactivating mutation in aromatase or a non-functional ERα had osteopenia and continued longitudinal growth after sexual maturation. The aim of the present study was to evaluate the role of different domains of ERα for the effects of E2 and SERMs on bone mass in males. Three mouse models lacking either ERαAF-1 (ERαAF-1(0)), ERαAF-2 (ERαAF-2(0)) or the total ERα (ERα(−/−)) were orchidectomized (orx) and treated with E2 or placebo. E2 treatment increased the trabecular and cortical bone mass and bone strength, while it reduced the thymus weight and bone marrow cellularity in orx wild type (WT) mice. These parameters did not respond to E2 treatment in orx ERα(−/−) or ERαAF-2(0) mice. However, the effects of E2 in orx ERαAF-1(0) mice were tissue-dependent, with a clear response in cortical bone parameters and bone marrow cellularity, but no response in trabecular bone. To determine the role of ERαAF-1 for the effects of SERMs, we treated orx WT and ERαAF-1(0) mice with Raloxifene (Ral), Lasofoxifene (Las), Bazedoxifene (Bza) or vehicle. These SERMs increased total body areal bone mineral density (BMD) and trabecular volumetric BMD to a similar extent in orx WT mice. Furthermore, only Las increased cortical thickness significantly and only Bza increased bone strength significantly. However, all SERMs showed a tendency towards increased cortical bone parameters. Importantly, all SERM-effects were absent in the orx ERαAF-1(0) mice. In conclusion, ERαAF-2 is required for the estrogenic effects on all evaluated parameters, while the role of ERαAF-1 is tissue specific. All evaluated effects of Ral, Las and Bza are dependent on a functional ERαAF-1. Our findings might contribute to the development of bone specific SERMs in males

Functions of estrogen receptor b in the metabolism of rodent bone

Estrogens are important for widespread biological functions including regulation of development and maintenance of skeletal tissue. The effects of estrogens are thought to be mediated via two intracellular proteins, estrogen receptors a and beta (ERalpha and ERbeta , respectively), which are expressed in most cell types in bone. In order to delineate the involvement of ERbeta in the development and maintenance of bone, we have analyzed mice depleted of functional ERbeta receptors following gene targeting. Both male and female homozygous ERbeta knockout (ERbetaKO) and wild-type (WT) mice were analyzed at different ages, corresponding to the phases of growth, maintenance and loss of bone. Adolescent, female ERbetaKO mice displayed increased cortical bone mineral content, resulting from increased dimensions of bone. Analysis of both bone formation and resorption markers at the mRNA level revealed an increase in bone formation markers, correlating with the increased bone growth. Overall, these data indicate that ERbeta limits bone growth during female puberty in WT mice. In contrast, male homozygous ERbetaKO mice displayed no apparent bone phenotype alterations at any age studied. Thus, the ERbeta protein is not critically involved in development or maintenance of bone in the male mouse, and a sex specific role of ERbeta is described. The cortical bone phenotype persisted in aged, 1 year-old, female ERbetaKO mice, which also exhibited higher trabecular bone mineral density than WT controls. Normal aging is associated with loss of trabecular bone, and this normal loss of bone was less pronounced in female ERbetaKO mice. Again, this could be correlated with an increase in specific markers related to bone formation. Furthermore, the expression of ERalpha was increased. In summary, these data indicate that, in young adults, ERbeta affects the cortical bone compartment, whereas later in adulthood ERbeta also regulates trabecular bone. In both stages ERbeta seems to act as a repressor, possibly by counteracting the stimulatory action of ERalpha on bone formation. To assess the role of individual ERs for the estrogen response in bone, ovariectomized WT, ERalphaKO, (ERalpha knockout), ERbetaKO and ERalphabetaPKO (ERalpha and ERbeta double knockout) mice treated with 17beta-estradiol were compared to vehicle-treated mice. Estrogen-treated WT and ERbetaKO mice, but not ERalphaKO or ERalphabetaKO mice, maintained a higher trabecular bone volume, which was associated with decreased osteoclast number and activity. As expected, the ERalphabetaKO mice did not respond to estrogentreatment by modifying the bone volume, or by modifying osteoclast activity, indicating that the osteoprotective effects of estrogen in ovariectomized mice do not invo lve ERalpha or ERbeta-independent mechanisms. The absence of osteoprotection in ERalphaKO mice was correlated with an increase in osteoclast parameters. Deletion of ERalpha thus renders the bone susceptible to a predominantly ERbeta-regulated increase in formation and activity of osteoclasts, indicating that estrogen can exert either inhibitory or stimulatory influences on bone resorption. In conclusion, the present study demonstrates that ERbeta affects bone in female mice, and the functional antagonism between the two ERs could provide an important means to control estrogen regulated bone metabolism

Mödrars upplevelser av att leva med ett barn som har cancersjukdom

Alla människor i Sverige under 18 år är barn. Varje år insjuknar 300 av dessa barn i cancer. När ett barn drabbas av cancer uppstår många olika upplevelser hos mödrarna. Syftet med denna studie var att belysa mödrars upplevelser av att leva med ett barn som har en cancersjukdom. Metoden som valdes var en kvalitativ analys av två självbiografiska böcker. Analysen utfördes i sex olika steg. Studien resulterade i två teman och fyra kategorier. Mödrarna kunde uppleva känslor som rädsla, maktlöshet, tillit och självkänsla. Det är viktigt att sjuksköterskan skapar sig en förståelse för hur mödrars upplevelser kan te sig för att sedan kunna ge en bra vård som innefattar både det sjuka barnet och modern

Mödrars upplevelser av att leva med ett barn som har cancersjukdom

Alla människor i Sverige under 18 år är barn. Varje år insjuknar 300 av dessa barn i cancer. När ett barn drabbas av cancer uppstår många olika upplevelser hos mödrarna. Syftet med denna studie var att belysa mödrars upplevelser av att leva med ett barn som har en cancersjukdom. Metoden som valdes var en kvalitativ analys av två självbiografiska böcker. Analysen utfördes i sex olika steg. Studien resulterade i två teman och fyra kategorier. Mödrarna kunde uppleva känslor som rädsla, maktlöshet, tillit och självkänsla. Det är viktigt att sjuksköterskan skapar sig en förståelse för hur mödrars upplevelser kan te sig för att sedan kunna ge en bra vård som innefattar både det sjuka barnet och modern