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Lopez TJ, Barcelos MA, Treesukosol Y. The administration of Exendin-4 and CCK affects food intake differentially in female and male rats tested on an alternate day fasting paradigm. Neurosci Lett 2023; 808:137275. [PMID: 37116572 DOI: 10.1016/j.neulet.2023.137275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/04/2023] [Accepted: 04/21/2023] [Indexed: 04/30/2023]
Abstract
Alternate day fasting (ADF) which involves the repetition of a 2-day cycle of a day of free access to food followed by a day of limited or no access to food, is an effective dietary intervention for weight loss in both humans and rats. We have previously reported that when presented with a high energy (HE) and standard chow diet, rats maintained on an ADF schedule displayed decreased HE diet preference compared to controls. Both male and female ADF rats increased overall intake of chow. However, this increase was driven by both meal size and meal number for males and only number of meals for females. Administration of cholecystokinin (CCK) or the glucagon-like peptide 1 (GLP-1) receptor agonist Exendin-4 (Ex-4) reduces food intake. It appears that CCK decreases food intake primarily through satiety signals whereas GLP-1 signaling may reduce intake by satiety and reward cues. Here, female and male rats were administered (i.p.) saline, 3.0 µg/kg Ex-4 (3 h before test), 3.0 µg/kg CCK (15 min before test) or a combination of both. Next, all rats were presented 23-h access to both HE diet and chow following food-restriction (ADF) or free access to chow (CON). Compared to saline-control sessions, administration of the combination of Ex-4 and CCK, but not Ex-4 or CCK alone, resulted in a decrease in both HE and chow intake early in the session for male ADF rats but the combination primarily decreased chow diet intake early in the session for female ADF rats. Thus, it appears that under these energy homeostatic conditions, administration of Ex-4 or CCK alone does not affect intake in ADF rats, but the combination produces decreases in feeding that are more than the sum of their individual effects. These findings support a role for the combination of GLP-1 and CCK signaling in the changes in diet preference induced by an alternate day fasting paradigm differentially in female and male rats.
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Affiliation(s)
- Taityana J Lopez
- Department of Psychology, California State University Long Beach, Long Beach CA 90840, USA
| | - Marc A Barcelos
- Department of Psychology, California State University Long Beach, Long Beach CA 90840, USA
| | - Yada Treesukosol
- Department of Psychology, California State University Long Beach, Long Beach CA 90840, USA.
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2
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Huang KP, Raybould HE. Estrogen and gut satiety hormones in vagus-hindbrain axis. Peptides 2020; 133:170389. [PMID: 32860834 PMCID: PMC8461656 DOI: 10.1016/j.peptides.2020.170389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/27/2020] [Accepted: 08/22/2020] [Indexed: 10/23/2022]
Abstract
Estrogens modulate different physiological functions, including reproduction, inflammation, bone formation, energy expenditure, and food intake. In this review, we highlight the effect of estrogens on food intake regulation and the latest literature on intracellular estrogen signaling. In addition, gut satiety hormones, such as cholecystokinin, glucagon-like peptide 1 and leptin are essential to regulate ingestive behaviors in the postprandial period. These peripheral signals are sensed by vagal afferent terminals in the gut wall and transmitted to the hindbrain axis. Here we 1. review the role of the vagus-hindbrain axis in response to gut satiety signals and 2. consider the potential synergistic effects of estrogens on gut satiety signals at the level of vagal afferent neurons and nuclei located in the hindbrain. Understanding the action of estrogens in gut-brain axis provides a potential strategy to develop estrogen-based therapies for metabolic diseases and emphasizes the importance of sex difference in the treatment of obesity.
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Affiliation(s)
- Kuei-Pin Huang
- School of Veterinary Medicine, University of California Davis, CA, United States
| | - Helen E Raybould
- School of Veterinary Medicine, University of California Davis, CA, United States.
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3
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Rivera HM, Stincic TL. Estradiol and the control of feeding behavior. Steroids 2018; 133:44-52. [PMID: 29180290 PMCID: PMC5864536 DOI: 10.1016/j.steroids.2017.11.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 12/21/2022]
Abstract
This review lays out the evidence for the role of E2 in homeostatic and hedonic feeding across several species. While significant effort has been expended on homeostatic feeding research, more studies for hedonic feeding need to be conducted (i.e. are there increases in meal size and enhanced motivation to natural food rewards). By identifying the underlying neural circuitry involved, one can better delineate the mechanisms by which E2 influences feeding behavior. By utilizing more selective neural targeting techniques, such as optogenetics, significant progress can be made toward this goal. Together, behavioral and physiological techniques will help us to better understand neural deficits that can increase the risk for obesity in the absence of E2 (menopause) and aid in developing therapeutic strategies.
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Affiliation(s)
- H M Rivera
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239, USA
| | - T L Stincic
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239, USA.
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4
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Resveratrol- and melatonin-abated ovariectomy and fructose diet–induced obesity and metabolic alterations in female rats. Menopause 2014; 21:876-85. [DOI: 10.1097/gme.0000000000000187] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Asarian L, Geary N. Sex differences in the physiology of eating. Am J Physiol Regul Integr Comp Physiol 2013; 305:R1215-67. [PMID: 23904103 DOI: 10.1152/ajpregu.00446.2012] [Citation(s) in RCA: 338] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating.
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Affiliation(s)
- Lori Asarian
- Institute of Veterinary Physiology and Center for Integrated Human Physiology, University of Zurich, Zurich, Switzerland; and
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6
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Mauvais-Jarvis F, Clegg DJ, Hevener AL. The role of estrogens in control of energy balance and glucose homeostasis. Endocr Rev 2013; 34:309-38. [PMID: 23460719 PMCID: PMC3660717 DOI: 10.1210/er.2012-1055] [Citation(s) in RCA: 793] [Impact Index Per Article: 72.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Estrogens play a fundamental role in the physiology of the reproductive, cardiovascular, skeletal, and central nervous systems. In this report, we review the literature in both rodents and humans on the role of estrogens and their receptors in the control of energy homeostasis and glucose metabolism in health and metabolic diseases. Estrogen actions in hypothalamic nuclei differentially control food intake, energy expenditure, and white adipose tissue distribution. Estrogen actions in skeletal muscle, liver, adipose tissue, and immune cells are involved in insulin sensitivity as well as prevention of lipid accumulation and inflammation. Estrogen actions in pancreatic islet β-cells also regulate insulin secretion, nutrient homeostasis, and survival. Estrogen deficiency promotes metabolic dysfunction predisposing to obesity, the metabolic syndrome, and type 2 diabetes. We also discuss the effect of selective estrogen receptor modulators on metabolic disorders.
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Affiliation(s)
- Franck Mauvais-Jarvis
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
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7
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Hirschberg AL. Sex hormones, appetite and eating behaviour in women. Maturitas 2012; 71:248-56. [PMID: 22281161 DOI: 10.1016/j.maturitas.2011.12.016] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 12/23/2011] [Indexed: 01/07/2023]
Abstract
Sex hormones play essential roles in the regulation of appetite, eating behaviour and energy metabolism and have been implicated in several major clinical disorders in women. Estrogen inhibits food intake, whereas progesterone and testosterone may stimulate appetite. This review describes recent findings concerning interactions between sex hormones and neuroendocrinological mechanisms in the control of appetite and eating in women. Furthermore, we are gaining insights into the roles played by sex hormones in the development of eating disorders and obesity. For instance, androgens may promote bulimia by stimulating appetite and reducing impulse control, a proposal supported by the observation that antiandrogenic treatment attenuates bulimic behaviour. Androgens are also involved in the pathophysiology of abdominal obesity in women. On the other hand, hormone replacement therapy with estrogen counteracts the weight gain and accumulation of abdominal fat associated with the menopausal transition. In conclusion, sex hormones and/or agents that exhibit similar activities may provide novel strategies for the treatment of eating disorders and android obesity, two of the most serious health problems for women today.
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Affiliation(s)
- Angelica Lindén Hirschberg
- Department of Women's and Children's Health, Karolinska Institutet and Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
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8
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Patel BP, Bellissimo N, Thomas SG, Hamilton JK, Anderson GH. Television viewing at mealtime reduces caloric compensation in peripubertal, but not postpubertal, girls. Pediatr Res 2011; 70:513-7. [PMID: 21772226 DOI: 10.1203/pdr.0b013e31822d783e] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The effect of television viewing (TVV) and pubertal status of 9- to 14-y-old girls on mealtime food intake (FI) after a premeal glucose drink was determined. On four separate mornings, girls randomly received equally sweetened drinks containing Sucralose (control) or glucose (1.0 g/kg body weight) in 250 mL of water 2 h after a standardized breakfast. FI from an ad libitum pizza meal was measured 30 min later with or without TVV. Appetite was measured at 15 min intervals to lunch and postmeal. TVV at mealtime had no effect on FI, however, glucose suppressed FI more with no TVV compared with TVV (24 versus 10%, p < 0.001), primarily because of its effect in peripubertal girls (p < 0.028). In postpubertal girls (n = 8), glucose reduced FI by ~27% in both the no TVV and TVV conditions, but in peripubertal girls (n = 17), reduction in FI was 22% without TVV and only 1% while TVV. Appetite correlated with FI at 30 min only in postpubertal girls. TVV at mealtime reduced caloric compensation after consumption of the glucose drink in peripubertal, but not postpubertal, girls, with no effect on mealtime FI. (Clinical trial number NCT01025687.)
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Affiliation(s)
- Barkha P Patel
- Department of Nutritional Sciences, University of Toronto, Ontario M5S 3E2, Canada
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9
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Abstract
During pregnancy, food intake and fat mass are increased to meet the energy demands of the growing conceptus and to prepare for the subsequent demands of lactation. A state of leptin resistance develops during pregnancy in the rat, which can facilitate the increase in food intake despite pregnancy-induced increases in leptin concentrations. Cholecystokinin (CCK) is a satiety factor that is released from the gut during feeding and acts to terminate short-term food intake. Circulating leptin concentrations can modulate the anorexic response to CCK; low leptin concentrations decrease the potency of CCK to reduce food intake. Because rats are leptin resistant by day 14 of pregnancy, it was hypothesised that the feeding response to CCK would be attenuated at that time. Nonpregnant and day 14 pregnant rats received an i.p. injection of CCK-8 (3 μg/kg body weight) or vehicle directly before the start of the dark phase. Food intake was measured 30 min after lights out. Approximately 90 min after receiving either CCK-8 or vehicle, rats were transcardially perfused with 4% paraformaldehyde. Food intake was significantly decreased in CCK-treated nonpregnant rats, although similar treatment did not reduce food intake in day 14 pregnant rats. CCK treatment lead to significant increased in c-Fos expression in the nucleus of the solitary tract (NTS) in both nonpregnant and pregnant rats compared to vehicle treatment, although the number of CCK-induced c-Fos positive cells was significantly less in pregnant rat compared to nonpregnant rats. Although CCK treatment increased the number of c-Fos positive cells in the hypothalamic paraventricular nucleus and supraoptic nucleus in nonpregnant rats, no significant increase was observed in these areas during pregnancy. These results indicate that pregnant rats are no longer responsive to the actions of CCK on short-term food intake and that CCK action in the NTS is reduced during pregnancy.
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Affiliation(s)
- S R Ladyman
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago, Dunedin, New Zealand.
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Fazliana M, Gu HF, Östenson CG, Yusoff MM, Wan Nazaimoon WM. Labisia pumila extract down-regulates hydroxysteroid (11-beta) dehydrogenase 1 expression and corticosterone levels in ovariectomized rats. J Nat Med 2011; 66:257-64. [PMID: 21833773 DOI: 10.1007/s11418-011-0575-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 07/25/2011] [Indexed: 11/25/2022]
Abstract
We evaluated the effects of a standardized Labisia pumila var. alata (LPva) extract on body weight change, hydroxysteroid (11-beta) dehydrogenase 1 (HSD11B1) expressions and corticosterone (CORT) level in ovariectomized (OVX) rats. The decoction of LPva has been used for generations among Malay women in Malaysia to maintain a healthy reproductive system.Thirty-six Sprague-Dawley OVX rats were treated orally with LPva extract (10, 20 or 50 mg/kg/day) or estrogen replacement (ERT) for 30 days. Sham operated rats were used as controls. Compared to untreated OVX rats, LPva-treated rats showed less weight gain and had significantly down-regulated HSD11B1 mRNA in liver tissues. HSD11B1 mRNA in adipose tissues increased by 55% (p < 0.05) in OVX rats but normalized in rats treated with LPva. Similarly, there was significant down-regulation (p < 0.05) of protein levels of HSD11B1 in both liver and adipose tissue of LPva and ERT groups, and CORT levels were significantly reduced in both groups of rats. This is the first study ever conducted to evaluate the beneficial effects of LPva in relation to weight gain caused by estrogen insufficiency. Results implied that the bioactive components in LPva extract affect not only HSD11B1 expressions in both adipose and liver tissues but also decrease circulating CORT. The extract should be explored for its potential use as a natural remedy for weight management.
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Affiliation(s)
- Mansor Fazliana
- Diabetes and Endocrine Unit, Cardiovascular, Diabetes and Nutrition Research Centre, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia.
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11
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Brown LM, Clegg DJ. Central effects of estradiol in the regulation of food intake, body weight, and adiposity. J Steroid Biochem Mol Biol 2010; 122:65-73. [PMID: 20035866 PMCID: PMC2889220 DOI: 10.1016/j.jsbmb.2009.12.005] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 11/19/2009] [Accepted: 12/15/2009] [Indexed: 12/14/2022]
Abstract
In recent years, obesity and its associated health disorders and costs have increased. Accumulation of adipose tissue, or fat, in the intra-abdominal adipose depot is associated with an increased risk of developing cardiovascular problems, type-2 diabetes mellitus, certain cancers, and other disorders like the metabolic syndrome. Males and females differ in terms of how and where their body fat is stored, in their hormonal secretions, and in their neural responses to signals regulating weight and body fat distribution. Men and post-menopausal women accumulate more fat in their intra-abdominal depots than pre-menopausal women, resulting in a greater risk of developing complications associated with obesity. The goal of this review is to discuss the current literature on sexual dimorphisms in body weight regulation, adipose tissue accrual and deposition.
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Affiliation(s)
- LM Brown
- Department of Nutrition, University of North Carolina Greensboro, Greensboro, NC 27412
| | - DJ Clegg
- Department of Internal Medicine, Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8854
- Corresponding author at: Deborah J. Clegg, RD, PhD, Assistant Professor, Department of Internal Medicine, Touchstone Diabetes Center, UT Southwestern Medical Center, 5323 Harry Hines Blvd., K5.252, Dallas, TX 75390-8854, Tel: 214-648-3401, Fax: 214-648-8720, (D. Clegg)
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12
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Okamoto S, Shimizu M, Mizuno A, Higuchi T. Estrogens inhibit food intake in CCK-1 receptor-deficient rats. J Physiol Sci 2010; 60:267-71. [PMID: 20495898 PMCID: PMC10717953 DOI: 10.1007/s12576-010-0094-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 04/13/2010] [Indexed: 02/03/2023]
Abstract
In human and many other animals, estrogens inhibit food intake and increases spontaneous activity. Previous studies hypothesized that the anorexigenic effect of estrogens is mediated by the cholecystokinin (CCK)-induced satiety effect. In the present study, we investigated whether estrogens-induced anorexigenic and hyper-active effects are present in Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rat, which is deficient in the CCK1 receptor. In OLETF rats with a regular 4-day estrous cycle, food intake decreased and spontaneous activity increased significantly more during estrus than diestrus as compared to control Long-Evans-Tokushima-Otsuka (LETO) rats. Subcutaneous injection of estradiol benzoate into ovariectomized OLETF rats significantly decreased feeding and increased spontaneous activity to the same extent as in LETO rats. These results suggest that the anorexigenic and hyper-active effects of estrogen can be mediated via pathways other than CCK-CCK1 receptor signaling pathway in CCK1 receptor-deficient rats.
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Affiliation(s)
- Shuichi Okamoto
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| | - Maki Shimizu
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| | - Akiko Mizuno
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| | - Takashi Higuchi
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
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13
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Estradiol and the control of food intake. Physiol Behav 2009; 99:175-80. [PMID: 19555704 DOI: 10.1016/j.physbeh.2009.06.010] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 06/10/2009] [Accepted: 06/12/2009] [Indexed: 01/19/2023]
Abstract
Gonadal steroids are among the many factors that influence food intake and body weight in mammals. Hormonal effects on these processes are particularly striking in female rats, which show large increases in food intake and body weight after ovariectomy. A key role of estradiol in the control of food intake and energy balance in humans is evidenced by the fact that the incidence of obesity increases greatly after menopause [American College of Obstetricians and Gynecologists. Body mass index and insulin resistance. Obstet Gynecol 2004;104:5s-10]. The actions of estradiol on neural systems that regulate eating may also account in part for sex differences in food intake and eating disorders, which occur much more frequently in young women [Sodersten P, Bergh C. Anorexia nervosa: towards a neurobiologically based therapy. Eur J Pharmacol 2003;480:67-74]. This paper presents a minireview of research examining the changes in feeding that occur during the ovarian cycle, the effects of estradiol withdrawal and replacement on food intake and body weight, and the neurobiological mechanisms by which estradiol influences feeding behavior. A model of hormone action on food intake that emerges from this research views estradiol as an indirect control of eating and meal size, producing changes in feeding behavior by modulating the central processing of both satiating and orexigenic peptides that represent direct controls of eating. Some of the shortcomings of the model and directions for future research are discussed.
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Asarian L, Geary N. Estradiol enhances cholecystokinin-dependent lipid-induced satiation and activates estrogen receptor-alpha-expressing cells in the nucleus tractus solitarius of ovariectomized rats. Endocrinology 2007; 148:5656-66. [PMID: 17823256 DOI: 10.1210/en.2007-0341] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Part of the mechanism through which estradiol, acting via estrogen receptor (ERalpha) signaling, inhibits feeding in rats and mice is increasing the satiating potency of cholecystokinin (CCK) acting on peripheral CCK-1 receptors. Ingested lipid is a principal secretagogue of intestinal CCK, and intraduodenal lipid infusions elicit CCK-mediated satiation in animals and humans. Here we tested whether estradiol affects the satiating potency of intraduodenal lipid infusions in ovariectomized rats and, using c-Fos immunocytochemistry, searched for potential brain sites of ERalpha involved. Food-deprived ovariectomized rats with open gastric cannulas sham fed 0.8 m sucrose 2 d after estradiol (estradiol benzoate, 10 mug, sc) or vehicle injection. Estradiol markedly increased the satiating potency of intraduodenal infusions of Intralipid but not the satiating potency of L-phenylalanine (10 min infusions, 0.44 ml/min, 0.13 kcal/ml), which in male rats satiates via a CCK-independent mechanism. Estradiol had no significant effect in rats pretreated with the CCK-1 receptor antagonist Devazepide (1 mg/kg, ip). The effect of estradiol on intraduodenal Intralipid-induced satiation was mirrored by selective increases in the number of cells expressing c-Fos immunoreactivity in a circumscribed region of the nucleus tractus solitarius (NTS), just caudal to the area postrema (cNTS) but not elsewhere in the NTS or the hypothalamic paraventricular or arcuate nuclei. In addition, a significant proportion of cNTS c-Fos-positive cells also expressed ERalpha. These data provide behavioral and cellular evidence that estradiol-ERalpha signaling in cNTS neurons increases the satiating potency of endogenous CCK released in response to ingested lipid.
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Affiliation(s)
- Lori Asarian
- Institute of Animal Science, ETH (Swiss Institute of Technology) Zürich, Schorenstrasse 16, Schwerzenbach, Switzerland.
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15
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Naessén S, Carlström K, Byström B, Pierre Y, Hirschberg AL. Effects of an antiandrogenic oral contraceptive on appetite and eating behavior in bulimic women. Psychoneuroendocrinology 2007; 32:548-54. [PMID: 17475412 DOI: 10.1016/j.psyneuen.2007.03.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 03/08/2007] [Accepted: 03/17/2007] [Indexed: 11/22/2022]
Abstract
High androgen levels in women with bulimia nervosa may promote bulimic behavior. The aim of the present study was to investigate the effects of an antiandrogenic oral contraceptive (OC) on appetite and eating behavior in women with bulimia nervosa compared to healthy controls. Twenty-one women with bulimia nervosa and 17 healthy controls matched for age and body mass index participated in the study. Basal and meal-related appetite and secretions of the satiety peptide cholecystokinin (CCK) and the appetite-stimulating peptide ghrelin were studied before and after 3 months of treatment with an antiandrogenic OC (30 microg ethinyl estradiol combined with 3 mg drospirenone). Bulimic behavior was evaluated in relation to changes in hormone levels. Before treatment, bulimic women had higher frequency of menstrual disturbances, acne and hirsutism and higher levels of testosterone but lower meal-related CCK secretion than controls. OC treatment reduced meal-related hunger and gastric distention in bulimics. CCK secretion in response to the meal was unchanged in bulimic women but decreased in the controls. Ghrelin secretion was comparable between groups and did not change in response to OC treatment. The treatment improved bulimic behavior in relation to a decline in testosterone levels in the entire group. Our results support the suggestion that androgens play a role in bulimic behavior. Treatment with an antiandrogenic OC may serve as a new strategy for treatment of bulimia nervosa and particularly in those patients with hyperandrogenic symptoms.
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Affiliation(s)
- S Naessén
- Department of Woman and Child Health, Division of Obstetrics and Gynecology, Karolinska Institute, Stockholm, Sweden.
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16
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Abstract
Several sex differences in eating, their control by gonadal steroid hormones and their peripheral and central mediating mechanisms are reviewed. Adult female rats and mice as well as women eat less during the peri-ovulatory phase of the ovarian cycle (estrus in rats and mice) than other phases, an effect under the control of cyclic changes in estradiol secretion. Women also appear to eat more sweets during the luteal phase of the cycle than other phases, possibly due to simultaneous increases in estradiol and progesterone. In rats and mice, gonadectomy reveals further sex differences: orchiectomy decreases food intake by decreasing meal frequency and ovariectomy increases food intake by increasing meal size. These changes are reversed by testosterone and estradiol treatment, respectively. A variety of peripheral feedback controls of eating, including ghrelin, cholecystokinin (CCK), glucagon, hepatic fatty acid oxidation, insulin and leptin, has been shown to be estradiol-sensitive under at least some conditions and may mediate the estrogenic inhibition of eating. Of these, most progress has been made in the case of CCK. Neurons expressing estrogen receptor-alpha in the nucleus tractus solitarius of the brainstem appear to increase their sensitivity to CCK-induced vagal afferent input so as to lead to an increase in the satiating potency of CCK, and consequently decreased food intake, during the peri-ovulatory period in rats. Central serotonergic mechanisms also appear to be part of the effect of estradiol on eating. The physiological roles of other peripheral feedback controls of eating and their central mediators remain to be established.
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17
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Geary N. Is the control of fat ingestion sexually differentiated? Physiol Behav 2004; 83:659-71. [PMID: 15621072 DOI: 10.1016/j.physbeh.2004.08.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2004] [Accepted: 08/04/2004] [Indexed: 12/11/2022]
Abstract
Sexual differentiation is a fundamental aspect of human physiology [Wizemann TM, Pardue M-L, editors. Exploring the biological contributions to human health: does sex matter? Washington DC, National Academy Press, 2001]. Therefore, this review considers whether the physiological control of eating, as related to dietary fat, is sexually differentiated. The effects of dietary fat are considered from the perspective of stimuli controlling eating that arise from oral, gastric, intestinal, hepatic, and adipose sites. The data reviewed provide substantial support for hypothesis that many such controls of fat ingestion are sexually differentiated in both humans and laboratory animals. Because as yet little is established definitively, however, the apparently most promising questions and methodologies for future work are emphasized.
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Affiliation(s)
- Nori Geary
- EW Bourne Laboratory, Weill Medical College of Cornell University, White Plains, NY 10506, USA.
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18
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Eckel LA. Estradiol: a rhythmic, inhibitory, indirect control of meal size. Physiol Behav 2004; 82:35-41. [PMID: 15234587 DOI: 10.1016/j.physbeh.2004.04.023] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2004] [Accepted: 04/02/2004] [Indexed: 11/21/2022]
Abstract
The classic analyses of the inhibitory effects of cholecystokinin (CCK) on meal size, conducted by Professor Gerard P. Smith and his colleagues at the Bourne Laboratory, inspired my initial interest in this field. My current research, which investigates the role of estradiol in the control of meal size, continues to be guided by Gerry's thoughtful, scientific approach to the study of ingestive behavior. In 1996, the year I arrived as a Postdoctoral Fellow at the Bourne Laboratory, Gerry published a new theory of the controls of meal size. In this important paper, Gerry proposed that the controls of meal size can be either direct or indirect. He argued that direct controls of meal size interact with peripheral, preabsorptive receptors that are sensitive to the chemical, mechanical, and colligative properties of ingested food and that indirect controls of meal size function to modulate the activity of direct controls. The purpose of this review is to illustrate how Gerry's theory has guided much of what is known about the mechanism by which estradiol inhibits food intake in female rats. I will provide evidence, primarily from behavioral studies of gonadally intact and ovariectomized rats, that estradiol exerts phasic and tonic inhibitory effects on food intake by acting as a rhythmic, inhibitory, indirect control of meal size.
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Affiliation(s)
- Lisa A Eckel
- Program in Neuroscience, Department of Psychology, Florida State University, Tallahassee, FL 32306-1270, USA.
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19
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Nilsson M, Naessén S, Dahlman I, Lindén Hirschberg A, Gustafsson JA, Dahlman-Wright K. Association of estrogen receptor beta gene polymorphisms with bulimic disease in women. Mol Psychiatry 2004; 9:28-34. [PMID: 14699439 DOI: 10.1038/sj.mp.4001402] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In this study, we explored the potential association between estrogen receptor beta (ERbeta) and disease in a group of bulimic women. Eating disorders are much more common in females than in males, suggesting a possible role for female sex hormone signalling in the pathogenesis of these diseases. Furthermore, estrogen has been implicated in appetite regulation. The occurrence of menstrual disturbances is also increased in bulimic women. We studied 76 bulimic women and 60 controls, and found an association between two common polymorphisms in the ERbeta gene with disease in this group of bulimic women. More detailed characterisation of the ERbeta gene identified a novel variant changing the primary structure of ERbeta protein in one bulimic patient. An initial functional characterization of this variant did not reveal any differences compared to the wild-type protein. Our findings point towards a possible role of ERbeta and/or neighboring genes in the etiology of disease in bulimic patients.
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Affiliation(s)
- M Nilsson
- Department of Biosciences, Karolinska Institute, Stockholm, Sweden.
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20
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Eckel LA, Houpt TA, Geary N. Estradiol treatment increases CCK-induced c-Fos expression in the brains of ovariectomized rats. Am J Physiol Regul Integr Comp Physiol 2002; 283:R1378-85. [PMID: 12429561 DOI: 10.1152/ajpregu.00300.2002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
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 microg 17beta-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 microg/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.
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Affiliation(s)
- Lisa A Eckel
- Weill Medical College of Cornell University and E.W. Bourne Behavioral Laboratory, New York Presbyterian Hospital, Westchester Division, White Plains New York 10509, USA.
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21
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Butera PC, Doerflinger AL, Roberto F. Cyclic estradiol treatment enhances the effects of interleukin-1beta on food intake in female rats. Brain Behav Immun 2002; 16:275-81. [PMID: 12009687 DOI: 10.1006/brbi.2001.0621] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Proinflammatory cytokines elicit behavioral and physiological responses that include decreased food intake, fever, and a general disinterest in usual activities. Ovarian hormones modulate immune system activity and responsiveness to cytokines in female mammals, suggesting that sex differences in immune function may be influenced by gonadal steroids. In this experiment, female adult rats were ovariectomized and given two daily subcutaneous injections of 5.0 or 20.0 microg of estradiol benzoate or the oil vehicle 3 weeks after surgery. Following 2 days of hormone treatment, animals received ip injections of interleukin-1beta (IL-1beta) or saline 1 h before light offset. Food and water intake was measured 2 h after light offset. The results indicate that a cyclic pattern of estradiol treatment enhances the anorectic effect of IL-1beta and suggest that responses to immune system activation are influenced by estradiol.
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Affiliation(s)
- Peter C Butera
- Department of Psychology, Niagara University, Niagara, NY 14109-2208, USA
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22
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Eckel LA, Geary N. Estradiol treatment increases feeding-induced c-Fos expression in the brains of ovariectomized rats. Am J Physiol Regul Integr Comp Physiol 2001; 281:R738-46. [PMID: 11506987 DOI: 10.1152/ajpregu.2001.281.3.r738] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
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 microg 17-beta 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.
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Affiliation(s)
- L A Eckel
- Weill Medical College of Cornell University, E. W. Bourne Behavioral Laboratory, White Plains, New York 10509, USA.
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23
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Abstract
Estradiol has long been known to inhibit feeding in animals, but the mechanism(s) mediating its effects have not been clear. Demonstrations that estradiol's feeding effects are expressed as decreases in meal size coupled with the emerging consensus that cholecystokinin (CCK) released from the small intestines during meals is a physiological negative-feedback signal controlling meal size (i.e. satiation) suggested a new approach to the problem of the mechanisms of estradiol's inhibitory effect on feeding. Progress on this approach is reviewed here. Experimental manipulations of exogenous and endogenous CCK and estradiol have produced converging evidence that estradiol cyclically increases the activity of the CCK satiation-signaling pathway so that meal size and food intake decrease during the ovulatory or estrus phase of the ovarian cycle. This is a striking example of the modulation of the operation of a control of meal size by the physiological context in which the meal occurs. Estradiol also produces a tonic decrease in meal size, but this apparently does not involve the CCK satiation-signaling pathway. Where and how estradiol acts to increase the potency of the CCK satiating-signaling pathway are not known. Several possible sites are suggested by the observations that estradiol treatment increases feeding- and CCK-induced expression of c-Fos in ovariectomized animals in brain areas including the nucleus tractus solitarius, paraventricular nucleus of the hypothalamus, and central nucleus of the amygdala. Tests with null mutation mice indicate that estrogen receptor-alpha is necessary for estradiol's feeding effects. Finally, the possibilities that estradiol exerts important influences on normal or disordered eating in women are discussed. It is concluded that estradiol exerts a biologically significant action on CCK satiation in animals. Further research to determine whether this action of estradiol has a role in the pathogenesis, course, or treatment of disordered eating in women is indicated.
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Affiliation(s)
- N Geary
- Weill Medical College of Cornell University, E. W. Bourne Laboratory, Department of Psychiatry, 21 Bloomingdale Road, White Plains, NY 10605, USA.
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24
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Abstract
In the almost 30 years since the ability of peripheral administration of the brain/gut peptide cholecystokinin (CCK) to inhibit food intake was first demonstrated, significant progress in our overall understanding of the role of CCK in ingestive behavior has been made. A physiologic role for endogenous CCK in the control of meal size has been demonstrated and sites and mechanisms of action for CCK in food intake have been investigated. Recent work has uncovered roles for the CCK satiety pathway in the mediation of the feeding modulatory actions of estradiol, insulin, and leptin. The availability of the Otsuka Long Evans Tokushima Fatty (OLETF) rat, a strain lacking CCK(A) receptors, provides a unique model for the study of how deficits in a within-meals satiety signaling pathway may result in long-term changes in food intake and body weight.
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Affiliation(s)
- T H Moran
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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25
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Abstract
Food intake and meal size are reduced in female Long-Evans rats during estrus. To investigate the contribution of the satiating action of endogenous cholecystokinin (CCK) to this, rats were injected with 1 mg/kg of the potent, selective CCK(A) receptor antagonist, devazepide, during diestrus, when meal size is maximal, and during estrus, when it is minimal. Devazepide increased spontaneous food intake and meal size during estrus, but not during diestrus. Meal frequency was not affected by devazepide treatment. These results indicate that the potency of the CCK satiety-signaling system increases during estrus.
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Affiliation(s)
- L A Eckel
- Joan and Sanford I. Weill Medical College of Cornell University, New York Presbyterian Hospital-Westchester Division, White Plains 10605, USA.
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26
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Asarian L, Geary N. Cyclic estradiol treatment phasically potentiates endogenous cholecystokinin's satiating action in ovariectomized rats. Peptides 1999; 20:445-50. [PMID: 10458513 DOI: 10.1016/s0196-9781(99)00024-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The influence of ovarian cycling and of exogenous estradiol on the cholecystokinin (CCK) satiety-signalling system was investigated in intact and ovariectomized Long-Evans rats, respectively. Intraperitoneal injection of 1 mg/kg devazepide, the most potent and selective CCK(A) receptor antagonist, increased test meal size during estrus, but not during diestrus, confirming the influence of hypothalamic-pituitary-gonadal function on CCK satiety in intact rats. Devazepide was then tested in ovariectomized rats that received chronic cyclic estradiol (2 microg estradiol benzoate on Tuesday and Wednesday each week) or oil treatment. Devazepide did not increase meal size in estradiol-treated rats on Tuesday, prior to estradiol treatment, compared to oil-treated rats, but did selectively increase meal size on Friday, late in the estradiol replacement cycle, compared to Tuesday, early in the cycle. These results suggest that a phasic potentiation of the endogenous CCK satiety-signalling system is part of the mechanism for the decrease in meal size in female rats during estrus.
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Affiliation(s)
- L Asarian
- Department of Psychiatry, Joan and Sandford I. Weill Medical College of Cornell University, New York Presbyterian Hospital, Westchester Division, White Plains 10605, USA
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27
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Hrupka BJ, Smith GP, Geary N. Ovariectomy and estradiol affect postingestive controls of sucrose licking. Physiol Behav 1997; 61:243-7. [PMID: 9035254 DOI: 10.1016/s0031-9384(96)00360-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ovariectomy (OVX) has been shown to increase, and estradiol replacement to decrease, meal size in rats. Because little is known about how estradiol influences meals, we conducted two experiments to examine the effects of OVX and beta-estradiol 3-benzoate (EB) replacement on the microstructure of licking behavior. In both experiments, patterns of licking were analyzed in adult female Sprague-Dawley rats during an 0.8 M sucrose test meal. In Experiment 1, meal microstructure was determined preOVX and 10-12 days postOVX. Rate of licking following OVX was not changed during min 1 of the meal, but was significantly faster during min 2-4 of the meal (p < 0.03). The numbers of bursts (runs of licks separated by 250-500 ms) and numbers of clusters (runs of licks separated by > 500 ms) were significantly increased during min 2-4 (p < 0.05). In Experiment 2, OVX rats received EB replacement. Rate of licking after EB replacement was not changed during min 1 of the meal, but was significantly slower during the remainder of the meal (min 2-4, min 5-7, and min 8-10). Burst size, cluster size, and interburst interval were less after EB replacement during min 5-7 of the test meal (all p < 0.05). Because both OVX and EB replacement failed to alter the rate of licking during min 1, estrogen did not appear to alter the palatability of sucrose. OVX and EB replacement did appear to affect a postingestive mechanism(s) that is engaged within 2-4 min of meal onset.
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Affiliation(s)
- B J Hrupka
- Department of Psychiatry, Cornell University Medical College, White Plains 10605, USA.
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28
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Geary N, Smith GP, Corp ES. The increased satiating potency of CCK-8 by estradiol is not mediated by upregulation of NTS CCK receptors. Brain Res 1996; 719:179-86. [PMID: 8782878 DOI: 10.1016/0006-8993(96)00099-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Estradiol benzoate (EB) increases the satiating effect of CCK-8 in ovariectomized rats. It is possible that this effect of EB is due to upregulation of CCKA receptors in the terminals of vagal afferent fibers because these receptors have been implicated in the mediation of the satiating effect of intraperitoneally injected CCK-8. To test this hypothesis, we used in vitro quantitative autoradiography to measure the effects of EB on the binding characteristics of CCK receptors in the nucleus tractus solitarius (NTS), a region that contains central terminal projections of abdominal vagal afferent fibers. As additional measures of EB's effects on CCK receptors, we also characterized EB's effects on CCK.8 binding in the area postrema (AP), a brain region rich in CCKA receptors, the ventromedial hypothalamus (VMH), a region rich in CCKB receptors, and in the pancreas, a gland rich in CCKA receptors. Saturation binding experiments were run using [125I]CCK-8 (approximately 40 pM, 2200 Ci/mmol) and 0.1-100 nM unlabelled CCK-8. EB did not change the number (Bmax) or affinity (Kd) of CCK receptors in the NTS. Furthermore, competition experiments with 500 nM of the selective CCKA receptor antagonist devazepide or the selective CCKB antagonist L365,260 demonstrated that EB failed to affect CCK receptor subtype number in the medial and lateral divisions of the NTS. EB also did not affect binding in the AP or VMH. These results do not confirm our hypothesis. The lack of effect of EB on vagal CCKA receptors in the NTS was not due to inappropriate conditions of tissue sampling or autoradiographic technique because EB increased the number, but not the affinity, of CCKA receptors in the pancreas significantly.
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Affiliation(s)
- N Geary
- Department of Psychiatry, Cornell University Medical College, White Plains, NY, USA
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29
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Hirschberg AL, Byström B, Carlström K, von Schoultz B. Reduced serum cholecystokinin and increase in body fat during oral contraception. Contraception 1996; 53:109-13. [PMID: 8838488 DOI: 10.1016/0010-7824(95)00265-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This investigation was undertaken to explore a possible role of the "satiety peptide" cholecystokinin and some other gastrointestinal hormones for changes in appetite and weight during oral contraception. Ten young healthy women attending a youth health care center for contraceptive counseling volunteered for the study. A standardized meal test was used for recordings of appetite and gastrointestinal hormone response before and after 5 months of treatment with a monophasic combined oral contraceptive. Body fat was calculated from measurements of skin-fold thickness. Oral contraceptives caused a suppression of basal levels of serum cholecystokinin, which was correlated to an increase in body fat. Meal-related response of cholecystokinin and appetite were not affected. Serum levels of gastrin and insulin were also unchanged, whereas triglycerides and postprandial glucose levels were elevated. The results suggest a role of cholecystokinin in regulation of body composition. Cholecystokinin stimulates the release of insulin and stimulates lipolysis in adipose tissue. Reduced cholecystokinin levels may, therefore, be related to mild impairment of glucose tolerance and promote body fat storage during oral contraception.
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Affiliation(s)
- A L Hirschberg
- Department of Obstetrics, Karolinska Hospital, Stockholm, Sweden
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30
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Uvnäs-Moberg K, Alster P, Petersson M. Dissociation of oxytocin effects on body weight in two variants of female Sprague-Dawley rats. INTEGRATIVE PHYSIOLOGICAL AND BEHAVIORAL SCIENCE : THE OFFICIAL JOURNAL OF THE PAVLOVIAN SOCIETY 1996; 31:44-55. [PMID: 8777160 PMCID: PMC7090716 DOI: 10.1007/bf02691480] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
As a counterpoint to studies that make a case for the use of oxytocin in short-term inhibition of food intake, the aim of the present study was to determine whether the peptide facilitates weight gain in female rats in a more long-term perspective. Two different variants of females Sprague-Dawley rats were used. The two variants differed in daily weight gain (0.38 g/day vs. 1.41 g/day during 28 days), and were designated slowly and rapidly growing rates (SGR and RGR) respectively. Oxytocin 1 mg/kg given s.c. to SGR for a five-day period increased weight gain significantly in comparison to a previous five-day period with NaCl-treatment (18.0 g/5 days versus 5.0 g/5 days; p < 0.01). In a separate study, oxytocin 1 mg/kg given for four days increased weight gain significantly in SGR versus saline-treated controls (7.5 g/4 days versus 1.6 g/4 days; p < 0.05). The weight-difference persisted six days later (p < 0.001). The weight increase of oxytocin occurred only during estrus (p < 0.05) and was not accompanied by any measurable increase in food intake. In RGR, oxytocin-treatment decreased food intake significantly (p < 0.001) and tended to decrease weight gain, although not significantly. The SGR and RGR also had different endocrine profiles with, for example, twice as high oxytocin (p < 0.01) and insulin levels (p < 0.01) in RGR compared to the SGR. These data suggest that oxytocin influences weight gain and food intake differently in the two variants of Sprague-Dawley rats, perhaps depending on factors such as endocrine profile and oxytocin sensitivity.
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Affiliation(s)
- K Uvnäs-Moberg
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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31
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Geary N, Trace D, Smith GP. Estradiol interacts with gastric or postgastric food stimuli to decrease sucrose ingestion in ovariectomized rats. Physiol Behav 1995; 57:155-8. [PMID: 7878110 DOI: 10.1016/0031-9384(94)00271-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The sham feeding preparation was used to determine whether systemic estradiol administration inhibits the intake of 0.8 M sucrose of ovariectomized rats by decreasing the potency of pregastric controls of ingestion. During real feeding, significant reductions in the sucrose intake of estradiol-treated rats appeared within 5-6 min. In contrast, estradiol had no effect on sham feeding at any time. The lack of effect of estradiol on sham feeding indicates that pregastric stimuli are not sufficient to mediate the inhibitory effect of estradiol on feeding in ovariectomized rats. Rather, because estradiol did inhibit real feeding, gastric and/or postgastric food stimuli are necessary for this inhibitory effect. The rapid onset of estradiol's inhibitory effect on real feeding suggests that these postingestive stimuli are selective for controls of the initial phase of the meal.
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Affiliation(s)
- N Geary
- Department of Psychiatry, Cornell University Medical College, White Plains, NY
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32
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Geary N, Trace D, McEwen B, Smith GP. Cyclic estradiol replacement increases the satiety effect of CCK-8 in ovariectomized rats. Physiol Behav 1994; 56:281-9. [PMID: 7938239 DOI: 10.1016/0031-9384(94)90196-1] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The influence of cyclic ovarian hormone replacement therapy on the satiety effect of exogenous CCK-8 was determined to investigate the mechanism mediating the preestrous decrease in meal size in female rats. Once weekly, food-deprived ovariectomized rats were IP injected with 0.5-4 micrograms/kg CCK-8 and offered 0.4-0.8 M sucrose 52 h after the second of two daily SC injections of 2.5 or 10 micrograms estradiol benzoate or vehicle and 4 h after 500 mg progesterone or vehicle. In each of three tests, estradiol significantly increased CCK-8's inhibitory effect on sucrose intake. In contrast, progesterone alone or in combination with estradiol did not consistently influence the satiating potency of CCK-8. The interaction of estradiol and CCK-8 was clearest for the dose of 4 micrograms/kg CCK-8. The interaction occurred during diurnal tests and during dark-onset tests in which estradiol did not decrease baseline sucrose intake. These results demonstrate that a cyclic regimen of estradiol replacement in ovariectomized rats is sufficient to enhance the satiating effect of exogenous CCK-8 and that simultaneous progesterone treatment does not influence this effect. Potentiation of the satiating effect of CCK released from the small intestine by ingested food may be one of the mechanisms by which food intake decreases during the period of high estrogen concentration in the estrus cycle.
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Affiliation(s)
- N Geary
- Department of Psychiatry, Cornell University Medical College, NY
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33
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Abstract
Recently, Melton, Kopman, and Riley (20) reported the rapid acquisition of drug discrimination learning using the sulfated form of cholecystokinin (CCK) within the conditioned taste aversion baseline of drug discrimination learning. The present study was designed to explore the receptor mediation of the stimulus properties of CCK within this procedure. Every fourth day, experimental subjects were given CCK-saccharin-LiCl pairings, and on the intervening recovery days, saccharin alone. Once discriminative control was established, doses of the CCK receptor antagonists devazepide (CCK-type A receptor subtype) and L-365,260 (CCK-type B receptor subtype) were administered in combination with the training dose of CCK. Unlike L-365,260 (1-1000 micrograms/kg), devazepide (1 microgram/kg) blocked the CCK stimulus, suggesting that within this design CCK's stimulus properties are mediated by the CCK-type A receptor subtype.
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Affiliation(s)
- P M Melton
- Department of Psychology, American University, Washington, DC 20016-8062
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34
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Butera PC, Bradway DM, Cataldo NJ. Modulation of the satiety effect of cholecystokinin by estradiol. Physiol Behav 1993; 53:1235-8. [PMID: 8346313 DOI: 10.1016/0031-9384(93)90387-u] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Data obtained from a wide variety of mammalian species indicate that feeding behavior can be influenced by changes in endogenous estrogens and by exogenous estrogenic treatments. The present experiment represents an initial investigation of the hypothesis that the suppression of food intake by estradiol is mediated by an enhancement of the satiety effect of cholecystokinin (CCK). Twenty-four female rats were ovariectomized and implanted either with a 5% estradiol silastic capsule or an empty capsule on the day of surgery. Three weeks later, animals received IP injections of CCK-octapeptide (5.0 or 10.0 micrograms/kg) or saline after 24-h food deprivation. Food and water intake were measured 60 min after treatment. Although CCK suppressed feeding in all subjects, the effects on food intake were greater in estradiol-treated females. CCK injections also reduced water intake, but there was no interaction between estradiol and CCK on drinking. These findings indicate that the inhibitory effect of CCK on food intake is enhanced in females treated with a physiological dose of estradiol, and suggest that the effects of estradiol on feeding behavior may be mediated by a potentiation of the satiety effect of CCK.
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Affiliation(s)
- P C Butera
- Department of Psychology, Niagara University, NY 14109
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35
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Abstract
Intraoral infusion of sucrose activates consummatory ingestive behaviour in rats selectively, i.e. the rat only emits the responses used to ingest food. Activation of consummatory ingestive behaviour in this way had no effect on the subsequent display of sexual behaviour by male or female rats and vice versa. Rats infused intraorally with sucrose and presented with a sexual partner showed ingestive and sexual behaviour simultaneously. Pretreatment with cholecystokinin octapeptide inhibited the ingestion of sucrose in both males and females but had no effect on the simultaneous display of sexual behaviour. Ingestion of sucrose from a drinking spout, a test in which the rat has to emit responses to obtain food, i.e. show appetitive ingestive behaviour, was inhibited by the presentation of a sexual partner in rats of both sexes. These results show that the mechanisms controlling consummatory sexual and ingestive behaviour operate independently and that the presentation of a sexual partner inhibits appetitive ingestive behaviour. Daily intraoral infusion of sucrose reduced pellet intake in ovariectomized rats while the rats maintained their body weight. Implantation of an oestradiol-filled implant reduced body weight and inhibited daily intake of pellets but had no effect on the intake of intraorally administered sucrose. Subsequent removal of the oestradiol implant increased sucrose intake and body weight but did not have a marked effect on pellet intake. Thus, rats respond to a lowering of the set point for body weight by decreasing their intake of the least preferable kind of food and increase their intake of the most preferable kind of food in response to an elevation of the set point for body weight. Ovariectomized rats infused intraorally once daily with a highly nutritive milk diet in the absence of food pellets ingested very large amounts and reduced their intake in response to oestradiol implantation. Thus, although oestradiol can inhibit consummatory ingestive behaviour, its suppressive effect on ingestion cannot be described in terms of selective effects on appetitive and/or consummatory aspects of the behaviour nor in terms of an alteration in the preference for a sweet solution. Inhibition of ingestive behaviour occurred within 24 h after oestrogen treatment as opposed to stimulation of sexual behaviour which had a longer latency, suggesting that oestradiol affects ingestive and sexual behaviour via different mechanisms. While the mechanisms controlling consummatory ingestive and sexual behaviour must be different, there is evidence for a common mechanism mediating the incentive motivation and reward aspects of these behaviours. The mechanisms which enable rats to select between two, possibly equally rewarding courses of action, i.e. display of sexual or ingestive responses, however, are unknown.
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Affiliation(s)
- J M Kaplan
- Department of Psychiatry and Clinical Research Centre, Karolinska Institute, S-141 86 Huddinge, Sweden
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36
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Abstract
A complete reproductive cycle of ovulation, conception, pregnancy, and lactation is one of the most energetically expensive activities that a female mammal can undertake. A reproductive attempt at a time when calories are not sufficiently available can result in a reduced return on the maternal energetic investment or even in the death of the mother and her offspring. Numerous physiological and behavioral mechanisms link reproduction and energy metabolism. Reproductive attempts may be interrupted or deferred when food is scarce or when other physiological processes, such as thermoregulation or fattening, make extraordinary energetic demands. Food deprivation suppresses both ovulation and estrous behavior. The neural mechanisms controlling pulsatile release of gonadotropin-releasing hormone (GnRH) and, consequently, luteinizing hormone secretion and ovarian function appear to respond to minute-to-minute changes in the availability of metabolic fuels. It is not clear whether GnRH-secreting neurons are able to detect the availability of metabolic fuels directly or whether this information is relayed from detectors elsewhere in the brain. Although pregnancy is less affected by fuel availability, both lactational performance and maternal behaviors are highly responsive to the energy supply. When a reproductive attempt is made, changes in hormone secretion have dramatic effects on the partitioning and utilization of metabolic fuels. During ovulatory cycles and pregnancy, the ovarian steroids, estradiol and progesterone, induce coordinated changes in the procurement, ingestion, metabolism, storage, and expenditure of metabolic fuels. Estradiol can act in the brain to alter regulatory behaviors, such as food intake and voluntary exercise, as well as adenohypophyseal and autonomic outputs. At the same time, ovarian hormones act on peripheral tissues such as adipose tissue, muscle, and liver to influence the metabolism, partitioning and storage of metabolic fuels. During lactation, the peptide hormones, prolactin and growth hormone, rather than estradiol and progesterone, are the principal hormones controlling partitioning and utilization of metabolic fuels. The interactions between metabolic fuels and reproduction are reciprocal, redundant, and ubiquitous; both behaviors and physiological processes play vital roles. Although there are species differences in the particular physiological and behavioral mechanisms mediating nutrition-reproduction interactions, two findings are consistent across species: 1) Reproductive physiology and behaviors are sensitive to the availability of oxidizable metabolic fuels. 2) When reproductive attempts are made, ovarian hormones play a major role in the changes in ingestion, partitioning, and utilization of metabolic fuels.
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Affiliation(s)
- G N Wade
- Department of Psychology and Neuroscience, University of Massachusetts, Amherst 01003
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Södersten P, Forsberg G, Bednar I, Lindén A, Qureshi GA. Cholecystokinin in the control of ingestive behavior. PROGRESS IN BRAIN RESEARCH 1992; 92:335-43. [PMID: 1302882 DOI: 10.1016/s0079-6123(08)61187-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- P Södersten
- Department of Psychiatry and Clinical Research Center, Karolinska Institute, Huddinge, Sweden
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Bednar I, Forsberg G, Lindén A, Qureshi GA, Södersten P. Involvement of dopamine in inhibition of food intake by cholecystokinin octapeptide in male rats. J Neuroendocrinol 1991; 3:491-6. [PMID: 19215497 DOI: 10.1111/j.1365-2826.1991.tb00308.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Abstract Deprivation of food reduced the level of dopamine in the cerebrospinal fluid of male rats and subsequent ingestion of food or intraperitoneal injection of Cholecystokinin octapeptide restored the level. Injection of a dopamine receptor agonist (apomorphine) or Cholecystokinin octapeptide inhibited food intake and these effects were reversed by pretreatment with a dopamine receptor antagonist (cis-flupentixol). Blockade of cholecystokinin-A receptors, by treatment with L-364,718, but not cholecystokinin-B receptors, by treatment with L-365,260, blocked the inhibitory effect of Cholecystokinin octapeptide on food intake but did not affect the inhibitory effect of apomorphine. It is suggested that Cholecystokinin interacts with dopamine in the control of food intake.
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Affiliation(s)
- I Bednar
- Department of Psychiatry and Clinical Research Centre, Karoiinska Institute, S-141 86 Huddinge, Sweden
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39
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Lindén A, Uvnäs-Moberg K, Forsbergt G, Bednar I, Södersten P. Involvement of cholecystokinin in food intake: I. Concentrations of cholecystokinin-like immunoreactivity in the cerebrospinal fluid of male rats. J Neuroendocrinol 1990; 2:783-9. [PMID: 19215419 DOI: 10.1111/j.1365-2826.1990.tb00641.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Abstract To investigate the role of central neural cholecystokinin in food intake the concentration of cholecystokinin-like immunoreactivity was measured by radioimmunoassay in the cerebrospinal fluid of male rats. Characterization of the molecular forms of Cholecystokinin was made by high-performance liquid chromatography before radioimmunoassay. Four molecular forms of cholecystokinin corresponding to standards of the tetra-, penta- and sulphated octapeptide and a late eluting peak probably corresponding to cholecystokinin-58 were found. The concentration of cholecystokinin-like immunoreactivity in the cerebrospinal fluid decreased in response to 48 h of food deprivation and was restored after 1 h of food intake, the main increase occurring within 30 min after the onset of feeding. Cholecystokinin-like immunoreactivity increased in the cerebrospinal fluid 10 min after an intraperitoneal injection of 5 mug cholecystokinin octapeptide, a dose which also suppressed the amount of food consumed during 1 h in rats deprived of food for 48 h. Intraperitoneal injection of the peripheral, cholecystokinin A receptor antagonists lorglumide (450 mug) or L-364. 718 (20 mug) reversed the inhibitory effect of cholecystokinin octapeptide on food intake and prevented the increase of cholecystokinin-like immunoreactivity in the cerebrospinal fluid. It is suggested that central neural cholecystokinin is involved in the control of food intake and that this is reflected in the alterations in cholecystokinin-like immunoreactivity in the cerebrospinal fluid which occur in response to food deprivation and food intake. However, a variety of ways of intracerebral administration of Cholecystokinin octapeptide failed to affect food intake in food-deprived rats. The possibility is raised that Cholecystokinin octapeptide acts in concert with another transmitter in the brain to affect food intake.
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Affiliation(s)
- A Lindén
- Department of Pharmacology, Karolinska Institute, S-104 01 Stockholm, Sweden
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Lindén A, Uvnäs-Moberg K, Forsberg G, Bednar I, Enerotht P, Södersten P. Involvement of Cholecystokinin in Food Intake: II. Lactational Hyperphagia in the Rat. J Neuroendocrinol 1990; 2:791-6. [PMID: 19215420 DOI: 10.1111/j.1365-2826.1990.tb00642.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Abstract The role of Cholecystokinin in the hyperphagia of lactation was studied by measuring the concentration of this hormone in plasma and cerebrospinal fluid in relation to food intake in lactating rats. Cholecystokinin was measured by high-performance liquid chromatography and radioimmunoassay in plasma and by radioimmunoassay in cerebrospinal fluid. Plasma concentrations of Cholecystokinin were increased in freely-fed lactating rats compared with non-lactating, regularly cycling rats. However, after 24 h of food deprivation the concentration of plasma Cholecystokinin was markedly decreased in the lactating rats to levels which were lower than those of non-lactating animals. Furthermore, plasma levels of Cholecystokinin did not increase in response to 1 h of feeding in lactating rats, whereas in non-lactating rats they did. In contrast, the concentration of cholecystokinin-like immunoreactivity in the cerebrospinal fluid was the same in freely-fed lactating and non-lactating rats. As in plasma, food deprivation markedly decreased the levels of cholecystokinin-like immunoreactivity in the cerebrospinal fluid of lactating rats but unlike in plasma, the levels were restored by feeding. The levels of cholecystokinin-like immunoreactivity were not changed under these conditions in the non-lactating rats. These results show that there is no correlation between the concentration of Cholecystokinin in plasma and cerebrospinal fluid, which supports the suggestion that the cholecystokinin-like immunoreactivity in the cerebrospinal fluid is derived from the brain. Removal of the litter from lactating rats deprived of food for 24 h reduced food intake and increased the concentration of cholecystokinin-like immunoreactivity in the cerebrospinal fluid, but not in plasma. The inhibition of food intake caused by an intraperitoneal injection of Cholecystokinin octapeptide increased after litter removal. It is suggested that hunger in the lactating rat is reflected by a decrease in the levels of cholecystokinin-like immunoreactivity in the cerebrospinal fluid and satiety by the restoration of these levels.
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Affiliation(s)
- A Lindén
- Department of Pharmacology, Karolinska Institute, S-104 01 Stockholm, Sweden
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Lindén A, Södersten P. Relationship between the concentration of cholecystokinin-like immunoreactivity in plasma and food intake in male rats. Physiol Behav 1990; 48:859-63. [PMID: 2087518 DOI: 10.1016/0031-9384(90)90240-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In food-deprived male rats IP injection of cholecystokinin octapeptide (CCK-8, 5 micrograms), ingestion of food or ejaculation caused a comparable increase in plasma concentrations of CCK-8 and inhibited food intake. IV injection of 0.1 microgram CCK-8 interrupted ongoing feeding and greatly increased plasma CCK-8 levels. Osmotic minipumps delivering 0.5 micrograms CCK-8/h implanted IP reduced meal size and caused a modest increase in plasma CCK-8 levels. Injection of 5 micrograms CCK-8 IP produced an abrupt but transient increase in plasma CCK-8 concentrations whereas plasma concentrations of CCK-8 increased gradually with feeding. Injection of 5 micrograms CCK-8 IP, but not feeding, caused a marked increase in plasma oxytocin levels. The suppression of feeding, but not the increase in oxytocin, induced by IP CCK-8 was reversed by ICV injection of the CCK antagonist proglumide in a dose (100 micrograms) which failed to affect food intake if injected IP. Deprivation of food decreased and feeding increased the concentration of CCK-like immunoreactivity in the CSF. It is suggested that CCK-8 inhibits feeding in physiological doses by a specific mechanism in which peripheral as well as central neural CCK is involved.
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Affiliation(s)
- A Lindén
- Department of Psychiatry, Karolinska Institute, Huddinge, Sweden
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