Effects of Conjugated Equine Estrogen With and Without Three Different Progestogens on Lipoproteins, High-Density Lipoprotein Subfractions, and Apolipoprotein A-I

Miller, Vincent; Muesing, Richard A.; LaRosa, John C.; Stoy, Diane B.; Phillips, Elizabeth A.; Stillman, Robert J.

doi:10.1097/00006250-199102000-00014

Cited by 103 publications

(23 citation statements)

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“…The changes in serum lipoprotein lipids shown by us are similar to those de¬ scribed by others. Miller et al (1991) used conjugated oestrogens at a similar dose to ours along with 150 µg DL-norgestrel (equivalent to 75 pg L-norgestrel) and al¬ though they measured serum lipoprotein lipids at 3 months rather than at 6 weeks as in the present study, they showed a non-statistical increase in triglycérides and HDL-cholesterol and a significant fall in serum total and LDL-cholesterol. However, Fletcher et al (1991) who used the combination of conjugated oestrogens with cyclical norgestrel at identical doses to those in our study showed almost identical serum lipoprotein lipid results to those described by us in the present study at 6 weeks.…”

Section: Discussionmentioning

confidence: 64%

Effects of hormone replacement therapy on platelet membrane fatty acid composition

Ranganath¹,

Christofides²,

Wright³

et al. 1996

Journal of Endocrinology

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Oestrogen replacement therapy has been shown to protect postmenopausal women from ischaemic heart disease, strokes and hypertension. The mechanism of protection conferred by oestrogen, although partly attributable to changes in serum lipoproteins, is not fully understood. The present study was undertaken to assess the effect of hormone replacement therapy on the composition of platelet membrane fatty acids in postmenopausal women. These were analysed by gas-liquid chromatography before and six weeks after continuous conjugated equine oestrogen therapy (0.625 mg daily) combined with cyclical therapy with 75 micrograms L-norgestrel from day 17 to 28 of a 28-day cycle. Each subject acted as her own control. The principal findings of the study were that, following treatment, there was a 16.2% reduction in platelet membrane polyunsaturated fatty acids (P < 0.001), an increase of 9.1 and 7.1% in saturated fatty acids and monounsaturated fatty acids respectively (P < 0.001) and a 17.8% reduction in arachidonic acid (P < 0.003). There was no correlation between changes in membrane fatty acids and serum lipoproteins. This suggests that the changes in membrane composition noted in this study may be a primary effect of hormone replacement therapy, especially oestrogen.

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Section: Discussionmentioning

confidence: 64%

Effects of hormone replacement therapy on platelet membrane fatty acid composition

Ranganath¹,

Christofides²,

Wright³

et al. 1996

Journal of Endocrinology

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“…(b) Reduced SHBG levels. Androgenic progestins, and to a much lesser extent MPA, also oppose the estrogeninduced increase in SHBG secretion by the liver [110,134,136,138]. Once again this effect is not exerted by the progesterone-like progestins [120,134,136].…”

Section: Metabolic Effects and Hepatocellular Actions Of Progestinsmentioning

confidence: 89%

Progestins and progesterone in hormone replacement therapy and the risk of breast cancer

Campagnoli

Clavel‐Chapelon

Kaaks

et al. 2005

The Journal of Steroid Biochemistry and Molecular Biology

116

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Controlled studies and most observational studies published over the last 5 years suggest that the addition of synthetic progestins to estrogen in hormone replacement therapy (HRT), particularly in continuous-combined regimen, increases the breast cancer (BC) risk compared to estrogen alone. By contrast, a recent study suggests that the addition of natural progesterone in cyclic regimens does not affect BC risk. This finding is consistent with in vivo data suggesting that progesterone does not have a detrimental effect on breast tissue. The increased BC risk found with the addition of synthetic progestins to estrogen could be due to the regimen and/or the kind of progestin used. Continuous-combined regimen inhibits the sloughing of mammary epithelium that occurs after progesterone withdrawal in a cyclic regimen. More importantly, the progestins used (medroxyprogesterone acetate and 19-Nortestosterone-derivatives) are endowed with some non-progesterone-like effects, which can potentiate the proliferative action of estrogens. Particularly relevant seem to be the metabolic and hepatocellular effects (decreased insulin sensitivity, increased levels and activity of insulin-like growth factor-I, and decreased levels of SHBG), which contrast the opposite effects induced by oral estrogen.

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“…Both progesterone and its receptor are necessary for successful pregnancy and birth [22-24]. In observational studies, progesterone acts in a vasoconstrictive way [25-28], while it exerts vasorelaxation effects on vascular tissue in vitro [29]. In animal studies, progestins have been reported to reverse the atheroprotective effects of E2 [30-33].…”

Section: Discussionmentioning

confidence: 99%

Sex-specific modification of progesterone receptor expression by 17β-oestradiol in human cardiac tissues

et al. 2010

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BackgroundAlthough circulating levels of sexual hormones in elderly men and women are low and quite similar, the adaptation of the elderly heart to stress differs between the sexes. We have hypothesized that the effects of sexual hormones in the heart may differ in men and women. Here, we assessed whether 17β-oestradiol regulates gene expression in the human heart in a sex-dependent manner. We selected the progesterone receptor as a well studied 17β-oestradiol target that may be pathologically linked to cardiac remodelling.MethodsIn order to assess the ex vivo effects of 17β-oestradiol in intact human cardiac tissues, we developed a 24-h model for the culture of human atrial myocardium. We verified tissue viability after 24 h in culture with two standard assays to determine the degree of apoptosis and metabolic activity of cardiac tissues. Progesterone receptor mRNA and protein level were measured after 24-h treatment of tissues with 17β-oestradiol. Statistical analysis was performed by the Mann-Whitney U test and two-way ANOVA.ResultsWe established a tissue culture model that allows for the study of viable human cardiac tissue over a 24-h period. After 24 h, cultured cardiac tissues revealed low apoptosis, retained their metabolic activity and, therefore, remained viable. Treatment with 17β-oestradiol led to an induction of the progesterone receptor mRNA level in female (P = 0.001) but not in male tissues. Similarly, there was an increase in the level of progesterone receptor protein in female tissues (P = 0.03), while a decreasing trend was observed in male tissues (P = 0.079) exposed to 17β-oestradiol.ConclusionsOur novel finding may offer a molecular explanation for the sex-specific differences observed in cardiac remodelling. The culture model we established for human cardiac tissue will facilitate the study of cellular processes in health and disease and will be of use for pharmacological testing.

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Effects of Conjugated Equine Estrogen With and Without Three Different Progestogens on Lipoproteins, High-Density Lipoprotein Subfractions, and Apolipoprotein A-I

Cited by 103 publications

References 0 publications

Effects of hormone replacement therapy on platelet membrane fatty acid composition

Effects of hormone replacement therapy on platelet membrane fatty acid composition

Progestins and progesterone in hormone replacement therapy and the risk of breast cancer

Sex-specific modification of progesterone receptor expression by 17β-oestradiol in human cardiac tissues

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