Ovarian function in Samoan women shows stronger association with signals of energy metabolism than fat reserves

Estrogens play an important role in the regulation of energy homeostasis in female mammals and a reduced ovarian function, due to natural aging or surgery, is associated with body weight increase and fat redistribution. This disruption of energy homeostasis may constitute a trigger for several pathologies known to be associated with climacterium; however, so far, limited attention has been devoted to the ability of estrogen replacement therapies (ERT) to reinstate the balanced energy metabolism characteristic of cycling female mammals. The purpose of the present study was to compare the efficacy of selected ERTs in reversing the ovariectomy-induced gain in body weight. To this aim female ERE-Luc mice were ovariectomized and, after 3 weeks, treated per os for 21 days with: conjugated estrogens, two selective estrogen receptor modulators (bazedoxifene and raloxifene), and the combination of bazedoxifene plus conjugated estrogens (tissue-selective estrogen complex, TSEC). The study shows that the therapy based on TSEC was the most efficacious in reducing the body weight accrued by ovariectomy (OVX). In addition, by means of in vivo imaging, the TSEC treatment was shown to increase estrogen receptor (ER) transcriptional activity selectively in the arcuate nucleus, which is a key area for the control of energy homeostasis. Finally, quantitative analysis of the mRNAs encoding orexigenic and anorexigenic peptides indicated that following ERT with TSEC there was a significant change in Agrp, NPY, and Kiss-1 mRNA accumulation in the whole hypothalamus. Considering that prior studies showed that ERT with TSEC was able to mimic the rhythm of ER oscillatory activity during the reproductive cycle and that such fluctuations were relevant for energy metabolism, the present observations further point to the ER tetradian oscillation as an important component of the ER signaling necessary for the full hormone action and therefore for an efficacious ERT.

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Genetic features of hormonal regulation of energy metabolism (literature review)

Actual problems of modern medicine ◽

10.26565/2617-409x-2019-4-02 ◽

2019 ◽

Keyword(s):

Energy Metabolism ◽

Hormonal Regulation ◽

Leptin Receptor ◽

Receptor Gene ◽

Subcutaneous Fat ◽

Leptin Resistance ◽

Fat Reserves ◽

Expression Of Genes ◽

Genes Encoding ◽

Genetic Features

Summary: Many chronic diseases are associated with impaired human energy metabolism and its hormonal regulation. According to the WHO, there are more than 300 million people with obesity in the world, 24.1% of the population are suffering from obesity in Ukraine. Being overweight is one of the main factors in the development of type 2 diabetes, cardiovascular and oncological diseases, pathology of the musculoskeletal and digestive systems, as well as reproductive dysfunction. Obesity is a multifactorial disease. According to the results presented in the literature, the accumulation of fat in the subcutaneous and visceral region will lead to a change in the expression of genes encoding proteins that regulate energy metabolism. Leptin belongs to the group of adipocyte hormones of subcutaneous fat. The expression of leptin is regulated by several hormones, including insulin and glucocorticoids, and starvation also leads to a decrease of leptin concentration in plasma. Leptin reduces hunger, activates the use of fats in energy metabolism and inhibits the excessive accumulation of fat reserves. Leptin resistance may occur due to the presence of a mutation or polymorphic variation in its receptor gene. One of the most studied and clinically significant polymorphic variants of the leptin receptor gene (LEPR) is the replacement of glutamine amino acid with arginine at 223 positions (Q223R), which leads to a decrease in the sensitivity of receptors to leptin. Mutations in POMC lead to obesity, which is accompanied by atrophy of the adrenal cortex and multiple disorders. Mutations in MC4R lead to obesity in patients but ensure normal sexual development and adequate functioning of the endocrine glands. Now scientists on the whole world are actively developing methods to fight obesity, based on stimulating the functioning of cascades of leptin-dependent signaling.

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Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134429 ◽

1990 ◽

Vol 48 (2) ◽

pp. 166-167

Author(s):

W.A. Jacob ◽

R. Hertsens ◽

A. Van Bogaert ◽

M. De Smet

Keyword(s):

Energy Metabolism ◽

Calcium Ions ◽

Energy Production ◽

Regulation Of Respiration ◽

Free Calcium ◽

Mitochondrial Matrix ◽

Cytochemical Study ◽

Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

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