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.

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

2001 ◽  
Vol 281 (3) ◽  
pp. R738-R746 ◽  
Author(s):  
Lisa A. Eckel ◽  
Nori Geary
Keyword(s):  
Food Intake ◽  
Neuronal Activity ◽  
Negative Feedback ◽  
Estradiol Benzoate ◽  
Brain Regions ◽  
Meal Size ◽  
Central Nucleus ◽  
Ovariectomized Rats ◽  
Estradiol Treatment ◽  
Multiple Regions

The steroid hormone estradiol decreases meal size by increasing the potency of negative-feedback signals involved in meal termination. We used c-Fos immunohistochemistry, a marker of neuronal activation, to investigate the hypothesis that estradiol modulates the processing of feeding-induced negative-feedback signals within the nucleus of the solitary tract (NTS), the first central relay of the neuronal network controlling food intake, and within other brain regions related to the control of food intake. Chow-fed, ovariectomized rats were injected subcutaneously with 10 μg 17-β estradiol benzoate or sesame oil vehicle on 2 consecutive days. Forty-eight hours after the second injections, 0, 5, or 10 ml of a familiar sweet milk diet were presented for 20 min at dark onset. Rats were perfused 100 min later, and brain tissue was collected and processed for c-Fos-like immunoreactivity. Feeding increased the number of c-Fos-positive cells in the NTS, the paraventricular nucleus of the hypothalamus (PVN), and the central nucleus of the amygdala (CeA) in oil-treated rats. Estradiol treatment further increased this response in the caudal, subpostremal, and intermediate NTS, which process negative-feedback satiation signals, but not in the rostral NTS, which processes positive-feedback gustatory signals controlling meal size. Estradiol treatment also increased feeding-induced c-Fos in the PVN and CeA. These results indicate that modest amounts of food increase neuronal activity within brain regions implicated in the control of meal size in ovariectomized rats and that estradiol treatment selectively increases this activation. They also suggest that estradiol decreases meal size by increasing feeding-related neuronal activity in multiple regions of the distributed neural network controlling meal size.

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.

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.

The anorectic hormone amylin contributes to feeding-related changes of neuronal activity in key structures of the gut-brain axis

2004 ◽  
Vol 286 (1) ◽  
pp. R114-R122 ◽  
Author(s):  
T. Riediger ◽  
D. Zuend ◽  
C. Becskei ◽  
T. A. Lutz
Keyword(s):  
Food Intake ◽  
Area Postrema ◽  
Peptide Hormone ◽  
Central Nucleus ◽  
Circumventricular Organ ◽  
Hypothalamic Area ◽  
Physiological Concentration ◽  
Lateral Parabrachial Nucleus ◽  
Neuronal Mechanisms ◽  
Fos Expression

Amylin is a peptide hormone that is cosecreted with insulin from the pancreas during and after food intake. Peripherally injected amylin potently inhibits feeding by acting on the area postrema (AP), a circumventricular organ lacking a functional blood-brain barrier. We recently demonstrated that AP neurons are excited by a near physiological concentration of amylin. However, the subsequent neuronal mechanisms and the relevance of endogenously released amylin for the regulation of food intake are poorly understood. Therefore, we investigated 1) amylin's contribution to feeding-induced c-Fos expression in the rat AP and its ascending projection sites, and 2) amylin's ability to reverse fasting-induced c-Fos expression in the lateral hypothalamic area (LHA). Similar to amylin (20 μg/kg sc), refeeding of 24-h food-deprived rats induced c-Fos expression in the AP, the nucleus of the solitary tract, the lateral parabrachial nucleus, and the central nucleus of the amygdala. In AP-lesioned rats, the amylin-induced c-Fos expression in each of these sites was blunted, indicating an AP-mediated activation of these structures. Pretreatment with the amylin antagonist AC-187 (1 mg/kg sc) inhibited feeding-induced c-Fos expression in the AP. Food deprivation activated LHA neurons, a response known to be associated with hunger. This effect was reversed within 2 h after refeeding and also in nonrefed animals that received amylin. In summary, our data provide the first evidence that feeding-induced amylin release activates AP neurons projecting to subsequent relay stations known to transmit meal-related signals to the forebrain. Activation of this pathway seems to coincide with an inhibition of LHA neurons.

Fos expression in brain stem nuclei of pregnant rats after hydralazine-induced hypotension

1999 ◽  
Vol 277 (2) ◽  
pp. R532-R540 ◽  
Author(s):  
Kathleen S. Curtis ◽  
J. Thomas Cunningham ◽  
Cheryl M. Heesch
Keyword(s):  
Area Postrema ◽  
Virgin Female ◽  
Female Rats ◽  
Ventrolateral Medulla ◽  
Pregnant Rats ◽  
Induced Hypotension ◽  
Central Response ◽  
Vehicle Treatment ◽  
Fos Expression ◽  
The Brain

Fos and dopamine β-hydroxylase immunoreactivity were evaluated in the brain stems of 21-day pregnant and virgin female rats injected with either hydralazine (HDZ; 10 mg/kg iv) or vehicle. HDZ produced significant hypotension in both groups, although baseline blood pressure was lower in pregnant rats (96 ± 2.5 mmHg) than in virgin female rats (121 ± 2.8 mmHg). There were no differences in Fos immunoreactivity in the brain stems of pregnant and virgin female rats after vehicle treatment. HDZ-induced hypotension significantly increased Fos expression in both groups; however, the magnitude of the increases differed in the caudal ventrolateral medulla (CVL), the area postrema (AP), and the rostral ventrolateral medulla (RVL). Fos expression after HDZ in pregnant rats was augmented in noncatecholaminergic neurons of the CVL but was attenuated in the AP and in noncatecholaminergic neurons in the RVL. These results are consistent with differences in the sympathetic response to hypotension between pregnant and virgin female rats and indicate that the central response to hypotension may be different in pregnant rats.

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.

scholarly journals Overexpression of Corticotropin Releasing Factor in the Central Nucleus of the Amygdala Advances Puberty and Disrupts Reproductive Cycles in Female Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3934-3944 ◽  
Author(s):  
X. F. Li ◽  
M. H. Hu ◽  
S. Y. Li ◽  
C. Geach ◽  
A. Hikima ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Hpa Axis ◽  
Pulse Generator ◽  
Female Rats ◽  
Central Nucleus ◽  
Ovariectomized Rats ◽  
Human Society ◽  
Central Administration ◽  
Corticosterone Secretion ◽  
Stress Changes

Abstract Prolonged exposure to environmental stress activates the hypothalamic-pituitary-adrenal (HPA) axis and generally disrupts the hypothalamic-pituitary-gonadal axis. Because CRF expression in the central nucleus of the amygdala (CeA) is a key modulator in adaptation to chronic stress, and central administration of CRF inhibits the hypothalamic GnRH pulse generator, we tested the hypothesis that overexpression of CRF in the CeA of female rats alters anxiety behavior, dysregulates the HPA axis response to stress, changes pubertal timing, and disrupts reproduction. We used a lentiviral vector to increase CRF expression site specifically in the CeA of preweaning (postnatal day 12) female rats. Overexpression of CRF in the CeA increased anxiety-like behavior in peripubertal rats shown by a reduction in time spent in the open arms of the elevated plus maze and a decrease in social interaction. Paradoxically, puberty onset was advanced but followed by irregular estrous cyclicity and an absence of spontaneous preovulatory LH surges associated with proestrous vaginal cytology in rats overexpressing CRF. Despite the absence of change in basal corticosterone secretion or induced by stress (lipopolysaccharide or restraint), overexpression of CRF in the CeA significantly decreased lipopolysaccharide, but not restraint, stress-induced suppression of pulsatile LH secretion in postpubertal ovariectomized rats, indicating a differential stress responsivity of the GnRH pulse generator to immunological stress and a potential adaptation of the HPA axis to chronic activation of amygdaloid CRF. These data suggest that the expression profile of this key limbic brain CRF system might contribute to the complex neural mechanisms underlying the increasing incidence of early onset of puberty on the one hand and infertility on the other attributed to chronic stress in modern human society.

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.

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