Estrogenic influence on the regulation of hepatic estrogen receptor-α and serum level of angiotensinogen in female rats

Stavréus-Evers, Anneli; Parini, Paolo; Freyschuss, Bo; Elger, W.; Reddersen, Gudrun; Sahlin, Lena; Eriksson, Håkan

doi:10.1016/s0960-0760(01)00077-2

Cited by 27 publications

(16 citation statements)

References 39 publications

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“…Interestingly, these differences were also depot specific with differences between omental and perigenital fatty tissue. The sex differences were also replicated in human fatty tissue (Park et al 2013) and may be linked to sex hormone regulation of AGT expression, which has been confirmed in laboratory rodents (Stavréus-Evers et al 2001;Ding et al 2001). The results of our study suggest that similar effects can be present in humans in the case of the ?11525 C/A (rs7079) polymorphism in miR-31 and miR-584 binding site of the angiotensinogen gene; sex-related differences in miRNA expression observed in the case of miR-31 (Rieger et al 2013) can be a contributing factor.…”

Section: Discussionsupporting

confidence: 82%

Polymorphism in miR-31 and miR-584 binding site in the angiotensinogen gene differentially influences body fat distribution in both sexes

et al. 2015

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Angiotensinogen (AGT), its active fragments and microRNA-31 (miR-31) play an important role in adipocyte differentiation. AGT contains a miR-31 polymorphic binding site. We hypothesize that the rs7079 polymorphism in the miR-31/584 binding site of the AGT gene could influence body fat distribution. A total of 751 subjects (195 men, 556 women) were enrolled in the study. The rs7079 genotypes were determined by qRT-PCR. Anthropometric measurements were taken on all subjects, who were subsequently divided into two groups: obese ([30 kg m -2 ) and non-obese (\30 kg m -2 ). Linear regression models were created to determine the contributions of sex, obesity status and rs7079 to all measured parameters. Adding the rs7079 genotype significantly contributed to the linear regression model for waist circumference (p = 0.013), hip circumference (p = 0.018) and supraspinal skin-fold thickness (p = 1 9 10 -3 ). Differences between sexes and between the obese and nonobese groups were observed. Waist circumference was lower in men carrying the A allele (p = 0.022); hip circumference was higher only in obese women carrying the A allele (p = 0.015). While men carrying the A allele had lower supraspinal skin-fold thickness (p = 0.022), this parameter was found to be higher in A allele carrying women (p = 3 9 10 -3 ). The higher total sum of skin-fold thickness in A allele carrying women was restricted to obese individuals (p = 0.028). The presence of the A allele was associated with both lower tricipital skin-fold thickness in non-obese women (p = 0.023) and a trend of higher thickness in non-obese men (p = 0.065). Significant associations of rs7079 in the AGT gene and body fat distribution were observed. The distribution followed opposing patterns in both sexes.

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Section: Discussionsupporting

confidence: 82%

Polymorphism in miR-31 and miR-584 binding site in the angiotensinogen gene differentially influences body fat distribution in both sexes

et al. 2015

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“…These hormone level variations in combination with the substantial intra-group variability (Table 2) produced by the injection regimen makes it an unpredictable mode of 17β-estradiol administration. However, we thought it of interest to compare the method of single daily injection to the other methods, because of its widespread use [5,6]. The rise in the concentration of 17β-estradiol seen in Gr.Inj towards the end of our experiment could be the effect of accumulation of the sesame oil containing the hormone in the animal adipose tissue.…”

Section: Discussionmentioning

confidence: 99%

“…. This is a frequently used injection dosage to achieve physiological levels of 17β-estradiol [5,6] Spånga, Sweden) were cut using a fine tooth saw and used to seal the silastic tubing, resulting in an oil-17β-estradiol-filled column 20 mm in length. The capsules were stored overnight in a vial containing sesame oil with the same concentration of 17β-estradiol as inside the capsules.…”

Section: Ovariectomy and Hormone Replacementmentioning

confidence: 99%

“…The difference of opinion on how to do this is most obvious in the choice of methods for administering 17β-estradiol. Three commonly used modes of administration are 1) subcutaneous injections [5][6][7][8][9], 2) inserting a commercially produced hormone pellet subcutaneously [8,[10][11][12][13] or 3) implanting a silastic capsule filled with 17β-estradiol subcutaneously in the animal [1,12,[14][15][16][17][18][19]. Another question concerns the choice of wash-out period between ovx and 17β-estradiol administration.…”

Section: Introductionmentioning

confidence: 99%

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Order of magnitude differences between methods for maintaining physiological 17β‐oestradiol concentrations in ovariectomized rats

Ström

Theodorsson²,

Theodorsson

2008

Scandinavian Journal of Clinical and Laboratory Investigation

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The use of animal, especially rat, models, is crucial for elucidating the biological effects and mechanisms of the widely used hormone 17β-estradiol. Unfortunately there is a lack of consensus on optimal means of obtaining and maintaining physiological 17β-estradiol concentrations in plasma.This may be the reason for varying results in several studies including the disagreement on whether 17β-estradiol is neuroprotective or not. Very few studies have been devoted to investigating the characteristics and biological relevance of different methods of 17β-estradiol administration. We therefore ovariectomized 75 Sprague-Dawley rats and, following a 2 weeks wash-out period, administered 17β-estradiol using three different methods; daily injections (10 µg 17β-estradiol/kg), slow-release pellets (0.25 mg 60 day-release pellets, 0.10 mg 90 day-release pellets) and silastic capsules (with/without wash-out periods) (silastic laboratory tubing, inner/outer diameter:1.575/3.175 mm, filled with 20 mm columns of 180 µg 17β-estradiol/mL sesame oil). Further 45 animals were used as ovariectomized and native controls, studied in different parts of the estrous cycle. Silastic capsules produced concentrations of 17β-estradiol within the physiological range for 4-5 weeks independent of whether a prior wash-out period was included or not. The slow-release pellets, irrespective of dose or release period, resulted in initial concentrations which were an order of magnitude above physiological concentrations during the first two weeks followed by a substantial decrease. Daily injections resulted in increasing 17β-estradiol concentrations, however within physiological levels. Silastic capsules are conveniently manufactured and used, and are superior to pellets and injections in reliably producing long-term 17β-estradiol concentrations within the physiological range.

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“…7,19 The reductions in both AT 1 receptors and angiotensin-converting enzyme should protect against an activation of the RAS. However, estradiol also causes release of angiotensinogen substrate from the liver, 20 and this could offset any potential protective effect if the renin enzyme is not working at maximal rate of reaction (Vmax), and thus renin activity is increased by increased angiotensinogen substrate leading to increased angiotensin II.…”

Section: Estrogen: "Good Girl"mentioning

confidence: 99%

Sex Steroids, Cardiovascular Disease, and Hypertension

2005

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Estrogenic influence on the regulation of hepatic estrogen receptor-α and serum level of angiotensinogen in female rats

Cited by 27 publications

References 39 publications

Polymorphism in miR-31 and miR-584 binding site in the angiotensinogen gene differentially influences body fat distribution in both sexes

Polymorphism in miR-31 and miR-584 binding site in the angiotensinogen gene differentially influences body fat distribution in both sexes

Order of magnitude differences between methods for maintaining physiological 17β‐oestradiol concentrations in ovariectomized rats

Sex Steroids, Cardiovascular Disease, and Hypertension

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