ICI 182,780 antagonizes the effects of estradiol on estrous behavior and energy balance in Syrian hamsters

1993 ◽  
Vol 265 (6) ◽  
pp. R1399-R1403 ◽  
Author(s):  
G. N. Wade ◽  
J. B. Powers ◽  
J. D. Blaustein ◽  
D. E. Green

Three experiments examined the effects of ICI 182,780, a steroidal "pure" antiestrogen that is thought to be active peripherally but not in the brain when given systemically, on energy balance, estrous behavior, and in vivo cell nuclear binding of [3H]estradiol in Syrian hamsters. Pretreatment with ICI 182,780 reduced in vivo uptake of [3H]estradiol in uterus but not in pooled hypothalamus-preoptic area. Ovariectomized Syrian hamsters were treated with estradiol benzoate (EB, 5 micrograms/day), ICI 182,780 (250 micrograms/day), or both EB and ICI 182,780 for 4 wk. Estradiol treatment caused significant decreases in food intake, body weight and fat content, and linear growth. Given alone, ICI 182,780 had no effect on these measures. When they were given concurrently, ICI 182,780 attenuated the effects of estradiol on body weight, growth, and fat content but not on food intake. Treatment with ICI 182,780 significantly diminished estrous behavior induced with either EB plus progesterone or with EB alone. These findings support the hypothesis that, in addition to its actions in the brain, estradiol acts peripherally to modulate estrous behavior and energy balance.

1993 ◽  
Vol 265 (3) ◽  
pp. R559-R562 ◽  
Author(s):  
G. N. Wade ◽  
J. B. Powers

Ovariectomized Syrian hamsters were treated with estradiol benzoate (5 micrograms/day for 4 wk), tamoxifen (500 micrograms/day), an antiestrogen that competes with estradiol for central and peripheral estrogen receptors, or both estradiol benzoate and tamoxifen. As expected, estradiol treatment caused significant decreases in body weight and fat content without affecting food intake. Given alone, tamoxifen had no effect on body weight or composition, but when given concurrently, tamoxifen significantly attenuated the effects of estradiol. These results stand in contrast to findings in rats where nonsteroidal antiestrogens, including tamoxifen, mimic the effects of estradiol on body weight and energy metabolism and are completely devoid of any antiestrogenic actions. As in rats, tamoxifen was a potent inhibitor of estrous behavior, whether induced with estradiol alone or with sequential treatment with estradiol and progesterone. Again, as in rats, tamoxifen acted as an antagonist and a weak estrogen agonist on uterine weight. These findings support the notion that the relative agonistic and antagonistic actions of tamoxifen, and other antiestrogens, vary with species and with the estrogen-sensitive endpoint being investigated.


2020 ◽  
Author(s):  
J Chalmers ◽  
YCL Tung ◽  
CH Liu ◽  
CJ O’Kane ◽  
S O’Rahilly ◽  
...  

AbstractMore than 300 genetic variants have been robustly associated with measures of human adiposity. Highly penetrant mutations causing human obesity do so largely by disrupting satiety pathways in the brain and increasing food intake. Most of the common obesity-predisposing variants are in, or near, genes that are expressed highly in the brain, but little is known about their function. Exploring the biology of these genes at scale in mammalian systems is challenging. We therefore sought to establish and validate the use of a multicomponent screen for feeding behaviour and nutrient status taking advantage of the tractable model organism Drosophila melanogaster. We validated our screen by demonstrating its ability to distinguish the effect of disrupting neuronal expression of four genes known to influence energy balance in flies from ten control genes. We then used our screen to interrogate two genetic data sets. Firstly, we investigated 53 genes that have been implicated in energy homeostasis by human genome wide association studies (GWASs): of the 53 Drosophila orthologues studied, we found that 16 significantly influenced feeding behaviour or nutrient status. Secondly, we looked at genes which are expressed and nutritionally responsive in specific populations of hypothalamic neurons involved in feeding/fasting (POMC and AgRP neurons): 50 Drosophila orthologues of 47 murine genes were studied, and 10 found by our screen to influence feeding behaviour or nutrient status in flies. In conclusion, Drosophila provide a valuable model system for high throughput interrogation of genes implicated in feeding behaviour and obesity in mammals.Author SummaryNew high-throughput technologies have resulted in large numbers of candidate genes that are potentially involved in the control of food intake and body-weight, many of which are highly expressed in the brain. How, though, are we to find the functionally most relevant genes from these increasingly long lists? Appetite needs to be explored in context of a whole animal, but studies in humans and mice take a long time and are expensive. The fruit fly, while clearly evolutionarily distant, shares a surprising amount of biology with mammals, with 75% of genes involved in inherited human diseases having an equivalent in flies. In particular, the fruit fly has surprisingly conserved neuronal circuitry when it comes to food intake. Here we have developed a suite of four different functional assays for studying the feeding behaviour and energy balance in flies. We then used these assays to explore the effects of disrupting the expression of genes in the neurons of flies, that either are implicated in body weight through human genetic studies or are expressed and nutritionally responsive in specific populations of neurons involved in feeding. We show that the use of fruit flies are time and cost efficient, and are a valuable model system for studying genes implicated in feeding behaviour and obesity in mammals.


1993 ◽  
Vol 265 (6) ◽  
pp. R1392-R1398 ◽  
Author(s):  
G. N. Wade ◽  
J. D. Blaustein ◽  
J. M. Gray ◽  
J. M. Meredith

ICI 182,780 is one of a new class of steroidal antiestrogens that differs from nonsteroidal antiestrogens, such as tamoxifen, in a number of respects. 1) It is bound by estrogen receptors with a high affinity, similar to that for estradiol. 2) It is a "pure" antiestrogen in that it does not mimic any of the effects of estradiol. 3) This class of antiestrogens does not seem to be bound by antiestrogen binding sites. 4) ICI 182,780 may not be active in the brain after peripheral administration. Indeed, ICI 182,780 blocked in vivo cell nuclear binding of [3H]estradiol in uterus, pituitary, and adipose tissue but not in hypothalamus-preoptic area. In vitro, ICI 182,780 competed for binding by neural estrogen receptors with an affinity comparable with that for estradiol. When given to ovariectomized rats, ICI 182,780 did not mimic any of the actions of estradiol. Instead, ICI 182,780 treatment completely blocked the uterotrophic effects of estradiol and attenuated the actions of estradiol on linear growth, carcass fat content, fat pad weight, and sexual receptivity. Treatment with ICI 182,780 also attenuated the estrogenic effects of tamoxifen on food intake, body weight and composition, linear growth, and uterine weight. These findings support the concept that, in addition to its actions in the brain, estradiol can act peripherally to modulate regulatory behaviors, energy balance, and estrous behavior. They are also consistent with the hypothesis that nonsteroidal antiestrogens, such as tamoxifen, affect energy balance via estrogen receptors, rather than antiestrogen binding sites.


2021 ◽  
Author(s):  
Alan C. Rupp ◽  
Abigail J. Tomlinson ◽  
Alison H. Affinati ◽  
Cadence True ◽  
Sarah R. Lindsley ◽  
...  

AbstractThe adipose-derived hormone leptin acts via its receptor (LepRb) in the brain to control energy balance. A previously unidentified population of GABAergic hypothalamic LepRb neurons plays key roles in the restraint of food intake and body weight by leptin. To identify markers for candidate populations of LepRb neurons in an unbiased manner, we performed single-nucleus RNA-sequencing of enriched mouse hypothalamic LepRb cells, as well as with total hypothalamic cells from multiple mammalian species. In addition to identifying known LepRb neuron types, this analysis identified several previously unrecognized populations of hypothalamic LepRb neurons. Many of these populations display strong conservation across species, including GABAergic Glp1r-expressing LepRb (LepRbGlp1r) neurons that express more Lepr and respond more robustly to exogenous leptin than other LepRb populations. Ablating LepRb from these cells provoked hyperphagic obesity without impairing energy expenditure. Conversely, reactivating LepRb in Glp1r-expressing cells decreased food intake and body weight in otherwise LepRb-null mice. Furthermore, LepRb reactivation in GABA neurons improved energy balance in LepRb-null mice, and this effect required the expression of LepRb in GABAergic Glp1r-expressing neurons. Thus, the conserved GABAergic LepRbGlp1r neuron population plays crucial roles in the control of food intake and body weight by leptin.


Endocrinology ◽  
2008 ◽  
Vol 149 (10) ◽  
pp. 5219-5226 ◽  
Author(s):  
Peter D. Alfinito ◽  
Xiaohong Chen ◽  
James Atherton ◽  
Scott Cosmi ◽  
Darlene C. Deecher

Previous reports suggest the antiestrogen ICI 182,780 (ICI) does not cross the blood-brain barrier (BBB). However, this hypothesis has never been directly tested. In the present study, we tested whether ICI crosses the BBB, penetrates into brain and hypothalamic tissues, and affects known neuroendocrine functions in ovariectomized rats. Using HPLC with mass spectrometry, ICI (1.0 mg/kg·d, 3 d) was detected in plasma and brain and hypothalamic tissues for up to 24 h with maximum concentrations of 43.1 ng/ml, and 31.6 and 38.8 ng/g, respectively. To evaluate antiestrogenic effects of ICI in the brain after systemic dosing, we tested its ability to block the effect of 17 α-ethinyl estradiol (EE) (0.3 mg/kg, 8 d) on tail-skin temperature abatement in the morphine-dependent model of hot flush and on body weight change. In the morphine-dependent model, EE abated 64% of the naloxone-induced tail-skin temperature increase. ICI pretreatment (1.0, 3.0 mg/kg·d) dose dependently inhibited this effect. ICI (3.0 mg/kg·d) alone showed estrogenic-like actions, abating 30% the naloxone-induced flush. In body weight studies, EE-treated rats weighed 58.5 g less than vehicle-treated rats after 8 d dosing. This effect was partially blocked by ICI (3.0 mg/kg·d) pretreatment. Similar to EE treatment, rats receiving 1.0 or 3.0 mg/kg·d ICI alone showed little weight gain compared with vehicle-treated controls. Thus, ICI crosses the BBB, penetrates into brain and hypothalamic tissues, and has both antiestrogenic and estrogenic-like actions on neuroendocrine-related functions.


2016 ◽  
Vol 48 (7) ◽  
pp. 491-501 ◽  
Author(s):  
Madeliene Stump ◽  
Deng-Fu Guo ◽  
Ko-Ting Lu ◽  
Masashi Mukohda ◽  
Xuebo Liu ◽  
...  

Peroxisome proliferator-activated receptor-γ (PPARγ), a master regulator of adipogenesis, was recently shown to affect energy homeostasis through its actions in the brain. Deletion of PPARγ in mouse brain, and specifically in the pro-opiomelanocortin (POMC) neurons, results in resistance to diet-induced obesity. To study the mechanisms by which PPARγ in POMC neurons controls energy balance, we constructed a Cre-recombinase-dependent conditionally activatable transgene expressing either wild-type (WT) or dominant-negative (P467L) PPARγ and the tdTomato reporter. Inducible expression of both forms of PPARγ was validated in cells in culture, in liver of mice infected with an adenovirus expressing Cre-recombinase (AdCre), and in the brain of mice expressing Cre-recombinase either in all neurons (NESCre/PPARγ-P467L) or selectively in POMC neurons (POMCCre/PPARγ-P467L). Whereas POMCCre/PPARγ-P467L mice exhibited a normal pattern of weight gain when fed 60% high-fat diet, they exhibited increased weight gain and fat mass accumulation in response to a 10% fat isocaloric-matched control diet. POMCCre/PPARγ-P467L mice were leptin sensitive on control diet but became leptin resistant when fed 60% high-fat diet. There was no difference in body weight between POMCCre/PPARγ-WT mice and controls in response to 60% high-fat diet. However, POMCCre/PPARγ-WT, but not POMCCre/PPARγ-P467L, mice increased body weight in response to rosiglitazone, a PPARγ agonist. These observations support the concept that alterations in PPARγ-driven mechanisms in POMC neurons can play a role in the regulation of metabolic homeostasis under certain dietary conditions.


Endocrinology ◽  
2021 ◽  
Author(s):  
Katharina Schnabl ◽  
Yongguo Li ◽  
Mueez U-Din ◽  
Martin Klingenspor

Abstract The obesity pandemic requires effective preventative and therapeutic intervention strategies. Successful and sustained obesity treatment is currently limited to bariatric surgery. Modulating the release of gut hormones is considered promising to mimic bariatric surgery with its beneficial effects on food intake, body weight and blood glucose levels. The gut peptide secretin was the first molecule to be termed a hormone; nevertheless, it only recently has been established as a legitimate anorexigenic peptide. In contrast to gut hormones that crosstalk with the brain either directly or by afferent neuronal projections, secretin mediates meal-associated brown fat thermogenesis to induce meal termination, thereby qualifying this physiological mechanism as an attractive, peripheral target for the treatment of obesity. In this perspective, it is of pivotal interest to deepen our yet superficial knowledge on the physiological roles of secretin as well as meal-associated thermogenesis in energy balance and body weight regulation. Of note, the emerging differences between meal-associated thermogenesis and cold-induced thermogenesis must be taken into account. In fact, there is no correlation between these two entities. In addition, the investigation of potential effects of secretin in hedonic-driven food intake, bariatric surgery as well as chronic treatment using suitable application strategies to overcome pharmacokinetic limitations will provide further insight into its potential to influence energy balance. The aim of this article is to review the facts on secretin’s metabolic effects, address prevailing gaps in our knowledge, and provide an overview on the opportunities and challenges of the therapeutic potential of secretin in body weight control.


Endocrinology ◽  
2019 ◽  
Vol 160 (10) ◽  
pp. 2441-2452 ◽  
Author(s):  
Tomokazu Hata ◽  
Noriyuki Miyata ◽  
Shu Takakura ◽  
Kazufumi Yoshihara ◽  
Yasunari Asano ◽  
...  

Abstract Anorexia nervosa (AN) results in gut dysbiosis, but whether the dysbiosis contributes to AN-specific pathologies such as poor weight gain and neuropsychiatric abnormalities remains unclear. To address this, germ-free mice were reconstituted with the microbiota of four patients with restricting-type AN (gAN mice) and four healthy control individuals (gHC mice). The effects of gut microbes on weight gain and behavioral characteristics were examined. Fecal microbial profiles in recipient gnotobiotic mice were clustered with those of the human donors. Compared with gHC mice, gAN mice showed a decrease in body weight gain, concomitant with reduced food intake. Food efficiency ratio (body weight gain/food intake) was also significantly lower in gAN mice than in gHC mice, suggesting that decreased appetite as well as the capacity to convert ingested food to unit of body substance may contribute to poor weight gain. Both anxiety-related behavior measured by open-field tests and compulsive behavior measured by a marble-burying test were increased only in gAN mice but not in gHC mice. Serotonin levels in the brain stem of gAN mice were lower than those in the brain stem of gHC mice. Moreover, the genus Bacteroides showed the highest correlation with the number of buried marbles among all genera identified. Administration of Bacteroides vulgatus reversed compulsive behavior but failed to exert any substantial effect on body weight. Collectively, these results indicate that AN-specific dysbiosis may contribute to both poor weight gain and mental disorders in patients with AN.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irene Cimino ◽  
Debra Rimmington ◽  
Y. C. Loraine Tung ◽  
Katherine Lawler ◽  
Pierre Larraufie ◽  
...  

AbstractNeuronatin (Nnat) has previously been reported to be part of a network of imprinted genes downstream of the chromatin regulator Trim28. Disruption of Trim28 or of members of this network, including neuronatin, results in an unusual phenotype of a bimodal body weight. To better characterise this variability, we examined the key contributors to energy balance in Nnat+/−p mice that carry a paternal null allele and do not express Nnat. Consistent with our previous studies, Nnat deficient mice on chow diet displayed a bimodal body weight phenotype with more than 30% of Nnat+/−p mice developing obesity. In response to both a 45% high fat diet and exposure to thermoneutrality (30 °C) Nnat deficient mice maintained the hypervariable body weight phenotype. Within a calorimetry system, food intake in Nnat+/−p mice was hypervariable, with some mice consuming more than twice the intake seen in wild type littermates. A hyperphagic response was also seen in Nnat+/−p mice in a second, non-home cage environment. An expected correlation between body weight and energy expenditure was seen, but corrections for the effects of positive energy balance and body weight greatly diminished the effect of neuronatin deficiency on energy expenditure. Male and female Nnat+/−p mice displayed subtle distinctions in the degree of variance body weight phenotype and food intake and further sexual dimorphism was reflected in different patterns of hypothalamic gene expression in Nnat+/−p mice. Loss of the imprinted gene Nnat is associated with a highly variable food intake, with the impact of this phenotype varying between genetically identical individuals.


Sign in / Sign up

Export Citation Format

Share Document