scholarly journals Fluoxetine Mimics the Anorectic Action of Estrogen and Its Regulation of Circadian Feeding in Ovariectomized Female Rats

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 849 ◽  
Author(s):  
Yuri Nishimura ◽  
Kaori Mabuchi ◽  
Natsumi Omura ◽  
Ayako Igarashi ◽  
Megumi Miura ◽  
...  
Keyword(s):  
Food Intake ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Body Weight Gain ◽  
Treated Group ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Dark Phase ◽  
Light Phase ◽  
Serotonergic Neurons ◽  
Fos Expression

Our previous study demonstrated that chronic estrogen replacement in ovariectomized rats reduces food intake and augments c-Fos expression in the suprachiasmatic nucleus (SCN), specifically during the light phase. Here, we hypothesized that serotonergic neurons in the central nervous system (CNS), which have anorectic action and play a role in regulating circadian rhythm, mediate the light phase-specific anorectic action of estrogen, and that selective serotonin reuptake inhibitors (SSRIs) mimic the hypophagic action of estrogen. Female Wistar rats were ovariectomized and treated with estradiol (E2) or cholesterol by subcutaneously implanting a silicon capsule containing E2 or cholesterol. Then, half of the cholesterol-treated rats were injected with the SSRI fluoxetine (5 mg/kg) (FLX group), while the remaining rats in the cholesterol-treated group (CON group) and all those in the E2 group were injected with saline subcutaneously twice daily at the onsets of the light and dark phases. Both E2 and FLX reduced food intake during the light phase but not the dark phase, and reduced body weight gain. In addition, both E2 and FLX augmented the c-Fos expression in the SCN, specifically during the light phase. These data indicate that FLX exerts estrogen-like antiobesity and hypophagic actions by modifying circadian feeding patterns, and suggest that estrogen regulates circadian feeding rhythm via serotonergic neurons in the CNS.

Estradiol treatment increases CCK-induced c-Fos expression in the brains of ovariectomized rats

2002 ◽  
Vol 283 (6) ◽  
pp. R1378-R1385 ◽  
Author(s):  
Lisa A. Eckel ◽  
Thomas A. Houpt ◽  
Nori Geary
Keyword(s):  
Food Intake ◽  
Area Postrema ◽  
Body Weight Gain ◽  
Meal Size ◽  
Female Rats ◽  
Central Nucleus ◽  
Ovariectomized Rats ◽  
Estradiol Treatment ◽  
Central Processing ◽  
Fos Expression

The ovarian hormone estradiol reduces meal size and food intake in female rats, at least in part by increasing the satiating potency of CCK. Here we used c-Fos immunohistochemistry to determine whether estradiol increases CCK-induced neuronal activation in several brain regions implicated in the control of feeding. Because the adiposity signals leptin and insulin appear to control feeding in part by increasing the satiating potency of CCK, we also examined whether increased adiposity after ovariectomy influences estradiol's effects on CCK-induced c-Fos expression. Ovariectomized rats were injected subcutaneously with 10 μg 17β-estradiol benzoate (estradiol) or vehicle once each on Monday and Tuesday for 1 wk ( experiment 1) or for 5 wk ( experiment 2). Two days after the final injection of estradiol or vehicle, rats were injected intraperitoneally with 4 μg/kg CCK in 1 ml/kg 0.9 M NaCl or with vehicle alone. Rats were perfused 60 min later, and brain tissue was collected and processed for c-Fos immunoreactivity. CCK induced c-Fos expression in the nucleus of the solitary tract (NTS), area postrema (AP), paraventricular nucleus of the hypothalamus (PVN), and central nucleus of the amygdala (CeA) in vehicle- and estradiol-treated ovariectomized rats. Estradiol treatment further increased this response in the caudal, subpostremal, and intermediate NTS, the PVN, and the CeA, but not in the rostral NTS or AP. This action of estradiol was very similar in rats tested before ( experiment 1) and after ( experiment 2) significant body weight gain, suggesting that adiposity does not modulate CCK-induced c-Fos expression or interact with estradiol's ability to modulate CCK-induced c-Fos expression. These findings suggest that estradiol inhibits meal size and food intake by increasing the central processing of the vagal CCK satiation signal.

scholarly journals Chronic oestrogen replacement in ovariectomised rats attenuates food intake and augments c-Fos expression in the suprachiasmatic nucleus specifically during the light phase

2011 ◽  
Vol 106 (8) ◽  
pp. 1283-1289 ◽  
Author(s):  
Akira Takamata ◽  
Kayo Torii ◽  
Kana Miyake ◽  
Keiko Morimoto
Keyword(s):  
Food Intake ◽  
Suprachiasmatic Nucleus ◽  
Female Rats ◽  
Dark Phase ◽  
Light Phase ◽  
Dark Cycle ◽  
Ovx Rats ◽  
Fos Expression ◽  
Insight Into ◽  
Ovariectomised Rats

Oestrogen replacement in ovariectomised (OVX) rats has been reported to attenuate food intake, especially during the light phase. To gain better insight into the central mechanism of oestrogen-induced reduction of food intake, we examined the effect of chronic oestrogen replacement in OVX rats on c-Fos expression in the suprachiasmatic nucleus (SCN) and on food intake during the light and dark phases. Eight-week-old female rats were ovariectomised and implanted with either an oestradiol (E2) or a vehicle pellet (Veh) subcutaneously. The animals were housed in an environment with a 12 h light–12 h dark cycle with the lights on at 07.00 hours. The amount of spontaneous food intake relative to each animal's body weight was significantly less for the E2 group than for the Veh group during the light phase, but there were no differences shown between these groups during the dark phase. There were no differences shown in the number of c-Fos-immunoreactive cells in the SCN in the E2 group compared with the Veh group during the early dark phase (22.00 hours; Zeitgeber time 15.00 (ZT15)), but the number was significantly higher than in the Veh group during the early light phase (10.00 hours; ZT3). This finding suggests that chronic oestrogen replacement chronically enhances SCN activity, specifically during the light phase. The oestrogen-induced enhancement of SCN activity during the light phase is possibly involved in the light phase-specific attenuation of food intake by oestrogen replacement in OVX rats.

Time course of effects of ovarian hormones on food intake and metabolism

1982 ◽  
Vol 243 (5) ◽  
pp. E407-E412 ◽  
Author(s):  
J. M. Gray ◽  
M. R. Greenwood
Keyword(s):  
Food Intake ◽  
Time Course ◽  
Body Weight Gain ◽  
Fatty Acid Synthetase ◽  
Hormone Treatment ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Treatment Groups ◽  
Adipose Tissue Lipoprotein Lipase

The effects of administration of estradiol benzoate (EB) or EB plus progesterone (EB + Prog) on feeding behavior and lipid metabolism were examined in ovariectomized rats killed 1, 2, 3, 7, or 14 days after the onset of hormone treatment. EB caused a transient decrease in food intake and body weight gain and a sustained decrease in adipose tissue lipoprotein lipase activity, and progesterone attenuated this EB effect. Hepatic acetyl CoA carboxylase (ACC) and fatty acid synthetase (FAS) activities decreased in the first days of hormone treatment (both EB and EB + Prog treatments) and returned to normal at 1 wk in both treatment groups. At 2 wk, hepatic ACC and FAS activities were greatly elevated in the EB, but not the EB + Prog group. These data demonstrate the complexity of the patterns of behavioral and metabolic responses after ovarian hormone manipulation in adult female rats.

scholarly journals Influence of exogenous and endogenous estrogen on thermoregulatory responses to mild heat and the interaction with light and dark phases

2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Shuri Marui ◽  
Yuta Masuda ◽  
Issei Kato ◽  
Kei Nagashima
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Dark Phase ◽  
Light Phase ◽  
Mild Heat ◽  
Thermoregulatory Responses ◽  
Endogenous Estrogen

AbstractThe present study aimed to determine the influence of estradiol (E2) and the interaction with circadian phases on thermoregulatory responses to mild heat in female rats. Heat loss and production during 3-h exposure to the environment at an ambient temperature of 28–34 °C were assessed by measuring abdominal temperature (Tabd), tail skin temperature, and oxygen consumption in ovariectomized rats with and without E2 replacement (OVX + E2 and OVX, respectively) and in control rats in the proestrus (P) and diestrus (D) phases. In the light phase, Tabd remained unchanged in all groups. Tabd increased in the dark phase, but was lower in the OVX + E2 and P groups than in the OVX and D groups. Oxygen consumption decreased at 34 °C, but to a lesser extent in the OVX + E2 group than in the OVX group. These results suggest that E2 activates thermoregulation in mild heat in the dark phase.

scholarly journals Effect of chronic infusion of olanzapine and clozapine on food intake and body weight gain in male and female rats

Life Sciences ◽  
2007 ◽  
Vol 81 (12) ◽  
pp. 1024-1030 ◽  
Author(s):  
SuJean Choi ◽  
Briana DiSilvio ◽  
JayLynn Unangst ◽  
John D. Fernstrom
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Body Weight Gain ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Chronic Infusion

Stimulation of food intake and weight gain in mature female rats by bovine prolactin and bovine growth hormone

1993 ◽  
Vol 264 (6) ◽  
pp. E986-E992 ◽  
Author(s):  
J. C. Byatt ◽  
N. R. Staten ◽  
W. J. Salsgiver ◽  
J. G. Kostelc ◽  
R. J. Collier
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Body Weight Gain ◽  
Mature Female ◽  
Female Rats ◽  
Bovine Growth Hormone ◽  
Female Rat ◽  
Moisture Percentage

Recombinant bovine prolactin (rbPRL) or bovine growth hormone (rbGH) was administered to mature female rats (10/treatment group) by daily subcutaneous injection for 10 days. Doses ranged from 7 to 5,000 micrograms/day (0.03-24 mg/kg body wt). Both rbPRL and rbGH increased body weight gain and food intake, but these parameters were increased at lower doses of rbPRL (7-63 micrograms/day) than rbGH (> 190 micrograms/day). Weight gain and food intake were maximally stimulated by 190 micrograms/day rbPRL, whereas maximal increased weight gain was obtained with the highest dose of rbGH (5,000 micrograms/day). Total carcass protein was increased by both hormones; however, protein as a percentage of body weight was unchanged. Similarly, neither rbPRL nor rbGH changed the percentage of carcass moisture. Percentage of body fat was increased by rbPRL but was decreased by rbGH. Weight of the gastrointestinal tract and kidneys was increased by both hormones, but increases were in proportion to body weight gain. These data confirm that ungulate prolactin is a hyperphagic agent in the female rat. In addition, they suggest that, while prolactin stimulates growth in mature female rats, this growth is probably not via a somatogenic mechanism.

Estrogens and antiestrogens: actions and interactions with fluphenazine on food intake and body weight in rats

1993 ◽  
Vol 264 (6) ◽  
pp. R1214-R1218 ◽  
Author(s):  
J. M. Gray ◽  
S. Schrock ◽  
M. Bishop
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Weight Gain ◽  
Food Intake ◽  
Ethinyl Estradiol ◽  
Body Weight Gain ◽  
Fatty Acid Synthetase ◽  
Ovariectomized Rats ◽  
Synthetase Activity ◽  
Concurrent Administration

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.

Peripheral oxytocin activates vagal afferent neurons to suppress feeding in normal and leptin-resistant mice: a route for ameliorating hyperphagia and obesity

2015 ◽  
Vol 308 (5) ◽  
pp. R360-R369 ◽  
Author(s):  
Yusaku Iwasaki ◽  
Yuko Maejima ◽  
Shigetomo Suyama ◽  
Masashi Yoshida ◽  
Takeshi Arai ◽  
...  
Keyword(s):  
Food Intake ◽  
Nucleus Tractus Solitarius ◽  
Body Weight Gain ◽  
Vagal Afferents ◽  
Afferent Neuron ◽  
Afferent Neurons ◽  
Vagal Afferent ◽  
Fos Expression ◽  
Novel Target ◽  
Anorexigenic Effect

Oxytocin (Oxt), a neuropeptide produced in the hypothalamus, is implicated in regulation of feeding. Recent studies have shown that peripheral administration of Oxt suppresses feeding and, when infused subchronically, ameliorates hyperphagic obesity. However, the route through which peripheral Oxt informs the brain is obscure. This study aimed to explore whether vagal afferents mediate the sensing and anorexigenic effect of peripherally injected Oxt in mice. Intraperitoneal Oxt injection suppressed food intake and increased c-Fos expression in nucleus tractus solitarius to which vagal afferents project. The Oxt-induced feeding suppression and c-Fos expression in nucleus tractus solitarius were blunted in mice whose vagal afferent nerves were blocked by subdiaphragmatic vagotomy or capsaicin treatment. Oxt induced membrane depolarization and increases in cytosolic Ca2+ concentration ([Ca2+]i) in single vagal afferent neurons. The Oxt-induced [Ca2+]i increases were markedly suppressed by Oxt receptor antagonist. These Oxt-responsive neurons also responded to cholecystokinin-8 and contained cocaine- and amphetamine-regulated transcript. In obese diabetic db/db mice, leptin failed to increase, but Oxt increased [Ca2+]i in vagal afferent neurons, and single or subchronic infusion of Oxt decreased food intake and body weight gain. These results demonstrate that peripheral Oxt injection suppresses food intake by activating vagal afferent neurons and thereby ameliorates obesity in leptin-resistant db/db mice. The peripheral Oxt-regulated vagal afferent neuron provides a novel target for treating hyperphagia and obesity.

Pattern of food intake and body weight gain in aged, noncycling female rats

1976 ◽  
Vol 18 (4) ◽  
pp. 551-561 ◽  
Author(s):  
Ralph L. Cooper ◽  
Markku Linnoila
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Body Weight Gain ◽  
Female Rats

scholarly journals Effects of Camellia Sinensis Extract on Repeated Restraint Stress-Induced Ovariectomized Female Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Minsook Ye ◽  
Daehyuk Jang ◽  
Jin Su Kim ◽  
Kyungsoo Kim ◽  
Insop Shim
Keyword(s):  
Glucose Metabolism ◽  
Camellia Sinensis ◽  
Tail Suspension Test ◽  
Treated Group ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Control Group ◽  
Stressful Situation ◽  
Repeated Restraint Stress ◽  
Menopausal Depression

The mortality of individuals suffering from depression has been increasing, noticeably of postmenopausal women; consequently, their care and treatment are significant to retain a high quality of life. The aim of this study was to examine the effect of Camellia sinensis (CS) on repeated stress-induced changes of the depression related function on the tail suspension test (TST), forced swimming test (FST) in ovariectomized female rats. After behavioral test, we evaluated the changes in the neurotransmitter by measuring the level of dopamine in the nucleus accumbens (NaC) and the serum levels of estrogen and oxytocin. We used 18F-2-fluoro-deoxy-D-glucose positron emission tomography (18F-FDG-PET) to examine the effects of CS on glucose metabolism in ovariectomized rats. Female rats were randomly segregated into three groups. Nor group was considered as nonoperated and nonstressed group, while the control was the ovariectomized and stressed group (OVX+ST), and CS was the ovariectomized, stressed and CS treated group. The rats were exposed to immobilization stress (IMO) for 14 d (2 h/d), and CS (300 mg/kg, i.p.) was treated 30 min before IMO stress. Significant reduction of immobility in the TST and FST was indicated in rats treatment with CS compared to the control group (OVX+ST). The levels of estrogen in the serum of the Nor and CS groups were significantly elevated compared to the OVX+ST group. Also, CS activated brain glucose metabolism in the cortex. The present findings suggested that CS had antidepressant effectiveness in a menopausal depression animal model. These findings suggest evidence that CS plays a crucial role in stressful situation, providing that CS might be a dependable antidepressant medicine to treat menopausal depression.

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