scholarly journals Palmitoylethanolamide Prevents Metabolic Alterations and Restores Leptin Sensitivity in Ovariectomized Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (4) ◽  
pp. 1291-1301 ◽  
Author(s):  
G. Mattace Raso ◽  
A. Santoro ◽  
R. Russo ◽  
R. Simeoli ◽  
O. Paciello ◽  
...  

It has been suggested a role of fatty acid ethanolamides in control of feeding behavior. Among these, palmitoylethanolamide (PEA) has not been directly implicated in appetite regulation and weight gain. The aim of this study was to investigate the effect of PEA on food intake and body weight and the interaction between PEA and hypothalamic leptin signaling in ovariectomized rats. Ovariectomy produced hyperphagia and increased weight gain, making it an useful model of mild obesity. Ovariectomized rats were treated with PEA (30 mg/kg sc) for 5 weeks. Then, blood was collected, and hypothalamus and adipose tissue were removed for histological, cellular, and molecular measurements. We showed that PEA caused a reduction of food intake, body weight, and fat mass. The mechanisms underlying PEA effects involved an improvement in hypothalamic leptin signaling, through a raise in signal transducer and activator of transcription 3 phosphorylation. We also reported that PEA reduced AMP-activated protein kinase-α phosphorylation and modulated transcription of anorectic and orexigenic neuropeptides in the hypothalamus. Moreover, PEA increased AMP-activated protein kinase-α phosphorylation and carnitine palmitoyltransferase 1 transcription in adipose tissue, suggesting an increase in ATP-producing catabolic pathway. PEA also polarized adipose tissue macrophages to M2 lean phenotype, associated to a reduction of inflammatory cytokines/adipokines. To demonstrate the direct effect of PEA on leptin sensitivity without interference of adiposity loss, we obtained consistent data in PEA-treated sham-operated animals and in vitro in SH-SY5Y neuroblastoma cell line. Therefore, our data provide a rationale for the therapeutic use of PEA in obese postmenopausal woman.

1993 ◽  
Vol 264 (6) ◽  
pp. R1214-R1218 ◽  
Author(s):  
J. M. Gray ◽  
S. Schrock ◽  
M. Bishop

Treatment of ovariectomized rats for 3 days with 2 micrograms estradiol benzoate (E2B), 6 micrograms ethinyl estradiol, or 1-2 mg of either of the antiestrogens nafoxidine or tamoxifen led to similar decreases in food intake, body weight gain, adipose tissue lipoprotein lipase activity, and hepatic fatty acid synthetase activity, despite their different effects on uterine growth and induction of progestin receptors in pituitary and adipose tissue. Longer-term (2 wk) treatment with tamoxifen resulted in similar transient changes in food intake and body weight gain, as did treatment with E2B. Daily administration of 50 micrograms fluphenazine (FLU) led to significant decreases in body weight, although there was no change in food intake. Concurrent administration of FLU with either E2B or tamoxifen led to additive effects on body weight and food intake change. None of the treatments had any effect on in vitro binding of [3H]tamoxifen to antiestrogen binding sites in pooled hypothalamic-preoptic area samples.


2011 ◽  
Vol 300 (6) ◽  
pp. E1002-E1011 ◽  
Author(s):  
Bart C. De Jonghe ◽  
Matthew R. Hayes ◽  
Ryoichi Banno ◽  
Karolina P. Skibicka ◽  
Derek J. Zimmer ◽  
...  

The adipose tissue-derived hormone leptin regulates energy balance through catabolic effects on central circuits, including proopiomelanocortin (POMC) neurons. Leptin activation of POMC neurons increases thermogenesis and locomotor activity. Protein tyrosine phosphatase 1B (PTP1B) is an important negative regulator of leptin signaling. POMC neuron-specific deletion of PTP1B in mice results in reduced high-fat diet-induced body weight and adiposity gain due to increased energy expenditure and greater leptin sensitivity. Mice lacking the leptin gene ( ob/ob mice) are hypothermic and cold intolerant, whereas leptin delivery to ob/ob mice induces thermogenesis via increased sympathetic activity to brown adipose tissue (BAT). Here, we examined whether POMC PTP1B mediates the thermoregulatory response of CNS leptin signaling by evaluating food intake, body weight, core temperature (TC), and spontaneous physical activity (SPA) in response to either exogenous leptin or 4-day cold exposure (4°C) in male POMC-Ptp1b-deficient mice compared with wild-type controls. POMC-Ptp1b −/− mice were hypersensitive to leptin-induced food intake and body weight suppression compared with wild types, yet they displayed similar leptin-induced increases in TC. Interestingly, POMC-Ptp1b −/− mice had increased BAT weight and elevated plasma triiodothyronine (T3) levels in response to a 4-day cold challenge, as well as reduced SPA 24 h after cold exposure, relative to controls. These data show that PTP1B in POMC neurons plays a role in short-term cold-induced reduction of SPA and may influence cold-induced thermogenesis via enhanced activation of the thyroid axis.


2018 ◽  
Vol 315 (1) ◽  
pp. E29-E37 ◽  
Author(s):  
Mariana Peduti Halah ◽  
Paula Beatriz Marangon ◽  
Jose Antunes-Rodrigues ◽  
Lucila L. K. Elias

Neonatal nutritional changes induce long-lasting effects on energy homeostasis. Adiponectin influences food intake and body weight. The aim of this study was to investigate the effects of neonatal nutritional programming on the central stimulation of adiponectin. Male Wistar rats were divided on postnatal (PN) day 3 in litters of 3 (small litter, SL), 10 (normal litter, NL), or 16 pups/dam (large litter, LL). We assessed body weight gain for 60 days, adiponectin concentration, and white adipose tissue weight. We examined the response of SL, NL, and LL rats on body weight gain, food intake, oxygen consumption (V̇o2), respiratory exchange ratio (RER), calorimetry, locomotor activity, phosphorylated-AMP-activated protein kinase (AMPK) expression in the hypothalamus, and uncoupling protein (UCP)-1 in the brown adipose tissue after central stimulus with adiponectin. After weaning, SL rats maintained higher body weight gain despite similar food intake compared with NL rats. LL rats showed lower body weight at weaning, with a catch up afterward and higher food intake. Both LL and SL groups had decreased plasma concentrations of adiponectin at PN60. SL rats had increased white adipose tissue. Central injection of adiponectin decreased body weight and food intake and increased V̇o2, RER, calorimetry, p-AMPK and UCP- 1 expression in NL rats, but it had no effect on SL and LL rats, compared with the respective vehicle groups. In conclusion, neonatal under- and overfeeding induced an increase in body weight gain in juvenile and early adult life. Unresponsiveness to central effects of adiponectin contributes to the imbalance of the energy homeostasis in adult life induced by neonatal nutritional programming.


2021 ◽  
Author(s):  
Ying Liu ◽  
Yu-chen Xu ◽  
Yu-gui Cui ◽  
Shi-wen Jiang ◽  
Fei-yang Diao ◽  
...  

Background Polycystic ovary syndrome (PCOS) is a common reproductive and metabolic disorder characterized by high androgen levels. The aim of this study was to evaluate the effects of hyperandrogenism on the hypothalamus, and subsequently on the food intake and obesity in females. Methods A dihydroxy testosterone (DHT)-induced rat model was established to recapitulate the hyperandrogenism features of PCOS patients. Body weight and food intake of the rats were recorded. The food intake of DHT-induced rats was restricted by pair feeding to exclude possible effects of weight gain on the hypothalamus. The expression levels of relevant proteins and mRNAs in the hypothalamus, primary hypothalamic neurons exposed to DHT were analyzed by Western blotting and RT-PCR respectively. The leptin levels in serum and cerebrospinal fluid (CSF) were measured, and leptin was injected via the intracerebroventricular (ICV) route to test the leptin sensitivity of hypothalamus. Results The excessive pre-puberty androgen levels in the DHT-induced rats markedly elevated food intake prior to weight gain. Consistent with this, the expression of NPY and Agouti-related peptide (Agrp) mRNAs were up-regulated, which occurred prior to obesity and even with restricted food intake. In addition, the hypothalamic sensitivity to insulin and leptin was also impaired in the DHT-induced rats before obesity and with restricted food intake. DHT significantly reduced the leptin levels in the CSF, and ICV injection of leptin inhibited the DHT-induced increase in food intake. Conclusions Androgen excess increased food intake in rats and promoted obesity by down-regulating insulin and leptin signaling in the hypothalamus, most likely by suppressing leptin levels in the CSF.


Endocrinology ◽  
2014 ◽  
Vol 155 (5) ◽  
pp. 1679-1689 ◽  
Author(s):  
Patricia Seoane-Collazo ◽  
Pablo B. Martínez de Morentin ◽  
Johan Fernø ◽  
Carlos Diéguez ◽  
Rubén Nogueiras ◽  
...  

Nicotine, the main addictive component of tobacco, promotes body weight reduction in humans and rodents. Recent evidence has suggested that nicotine acts in the central nervous system to modulate energy balance. Specifically, nicotine modulates hypothalamic AMP-activated protein kinase to decrease feeding and to increase brown adipose tissue thermogenesis through the sympathetic nervous system, leading to weight loss. Of note, most of this evidence has been obtained in animal models fed with normal diet or low-fat diet (LFD). However, its effectiveness in obese models remains elusive. Because obesity causes resistance towards many factors involved in energy homeostasis, the aim of this study has been to compare the effect of nicotine in a diet-induced obese (DIO) model, namely rats fed a high-fat diet, with rats fed a LFD. Our data show that chronic peripheral nicotine treatment reduced body weight by decreasing food intake and increasing brown adipose tissue thermogenesis in both LFD and DIO rats. This overall negative energy balance was associated to decreased activation of hypothalamic AMP-activated protein kinase in both models. Furthermore, nicotine improved serum lipid profile, decreased insulin serum levels, as well as reduced steatosis, inflammation, and endoplasmic reticulum stress in the liver of DIO rats but not in LFD rats. Overall, this evidence suggests that nicotine diminishes body weight and improves metabolic disorders linked to DIO and might offer a clear-cut strategy to develop new therapeutic approaches against obesity and its metabolic complications.


Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5654-5661 ◽  
Author(s):  
Ren Zhang ◽  
Harveen Dhillon ◽  
Huali Yin ◽  
Akihiko Yoshimura ◽  
Bradford B. Lowell ◽  
...  

Suppressor of cytokine signaling 3 (Socs3) has been identified as a mediator of central leptin resistance, but the identity of specific neurons in which Socs3 acts to suppress leptin signaling remains elusive. The ventromedial hypothalamus (VMH) was recently shown to be an important site for leptin action because deleting leptin receptor within VMH neurons causes obesity. To examine the role of VMH Socs3 in leptin resistance and energy homeostasis, we generated mice lacking Socs3 specifically in neurons positive for steroidogenic factor 1 (SF1), which is expressed abundantly in the VMH. These mice had increased phosphorylation of signal transducer and activator of transcription-3 in VMH neurons, suggesting improved leptin signaling, and consistently, food intake and weight-reducing effects of exogenous leptin were enhanced. Furthermore, on either chow or high-fat diets, these mice had reduced food intake. Unexpectedly, energy expenditure was reduced as well. Mice lacking Socs3 in SF1 neurons, despite no change in body weight, had improved glucose homeostasis and were partially protected from hyperglycemia and hyperinsulinemia induced by high-fat diets. These results suggest that Socs3 in SF1 neurons negatively regulates leptin signaling and plays important roles in mediating leptin sensitivity, glucose homeostasis, and energy expenditure.


1981 ◽  
Vol 240 (5) ◽  
pp. E499-E503 ◽  
Author(s):  
S. M. Schwartz ◽  
G. N. Wade

The effects of estradiol and progesterone on food intake, body weight, carcass adiposity, and adipose tissue lipoprotein lipase (LPL) activity were investigated in weanling female rats. Treatment with estradiol benzoate (EB) reduced body weight gain in ovariectomized (OVX) weanlings as it does in adults. However, other responses to EB were attenuated or absent in weanlings. EB treatment did not reduce food intake, carcass adiposity, or adipose tissue LPL activity. This impaired responsiveness to EB may be due to decreased levels of cytoplasmic estrogen receptors in liver and adipose tissue (but not hypothalamus) in weanlings. On the other hand, responsiveness to progesterone was adultlike in weanlings. Treatment of OVX, EB-primed weanlings with progesterone increased food intake, body weight gain, and carcass adiposity. This adultlike responsiveness to progesterone was associated with adultlike levels of adipose tissue progestin receptors. However, progesterone treatment did not increase adipose tissue LPL activity in weanlings, indicating that changes in LPL activity are not necessary for progesterone-induced obesity.


1987 ◽  
Vol 252 (2) ◽  
pp. E202-E208 ◽  
Author(s):  
K. Tokuyama ◽  
J. Himms-Hagen

Adrenalectomy normalizes many abnormalities of the obese (ob/ob) mouse. The high corticosterone concentration in blood may account in part for development of obesity and other abnormalities in the ob/ob mouse. Our objective was to determine dose-response relationships for the effect of corticosterone on the obesity. Lean and ob/ob mice were adrenalectomized or sham-operated at 4.5 wk of age. Adrenalectomized mice received 100 mg implants of cholesterol containing corticosterone (0, 2, 5, 20, or 50 mg) at 8.5 wk of age and were killed at 10.5 wk of age. In ob/ob mice, but not in lean mice, low physiological levels of serum corticosterone (up to 10 micrograms/dl) markedly increased body weight gain, food intake, and serum insulin. They also increased white and brown adipose tissue weights and decreased brown adipose tissue mitochondrial GDP binding. Higher levels of corticosterone (12-22 micrograms/dl) increased body weight gain, white and brown adipose tissue weights, and serum insulin and suppressed brown adipose tissue mitochondrial GDP binding in lean mice also, although in most cases to a lesser extent than in ob/ob mice, but were still without effect on food intake. Only very high levels of corticosterone (approximately 30 micrograms/dl) increased food intake in lean mice. Hyperglycemia was induced in ob/ob, but not lean, mice only at concentrations of corticosterone greater than 17 micrograms/dl. Thermoregulation was unaffected by serum corticosterone at levels from 0 to 30 micrograms/dl in both ob/ob and lean mice. Thus the ob/ob mouse is excessively sensitive and responsive to an effect of physiological levels of corticosterone that results in hyperphagia, hyperinsulinemia, and increased weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)


Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 642-650 ◽  
Author(s):  
Ignasi Canals ◽  
María C. Carmona ◽  
Marta Amigó ◽  
Albert Barbera ◽  
Analía Bortolozzi ◽  
...  

Sodium tungstate is a novel agent in the treatment of obesity. In diet-induced obese rats, it is able to reduce body weight gain by increasing energy expenditure. This study evaluated the role of leptin, a key regulator of energy homeostasis, in the tungstate antiobesity effect. Leptin receptor-deficient Zucker fa/fa rats and leptin-deficient ob/ob mice were treated with tungstate. In lean animals, tungstate administration reduced body weight gain and food intake and increased energy expenditure. However, in animals with deficiencies in the leptin system, treatment did not modify these parameters. In ob/ob mice in which leptin deficiency was restored through adipose tissue transplantation, treatment restored the tungstate-induced body weight gain and food intake reduction as well as energy expenditure increase. Furthermore, in animals in which tungstate administration increased energy expenditure, changes in the expression of key genes involved in brown adipose tissue thermogenesis were detected. Finally, the gene expression of the hypothalamic neuropeptides, Npy, Agrp, and Cart, involved in the leptin regulation of energy homeostasis, was also modified by tungstate in a leptin-dependent manner. In summary, the results indicate that the effectiveness of tungstate in reducing body weight gain is completely dependent on a functional leptin system. Anti-obesity activity of tungstate is due to an increase in thermogenesis and a reduction in food intake and depends entirely on a functional leptin system.


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