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AOYAMA M, NEGISHI A, ABE A, MAEJIMA Y, SUGITA S. Short-term transportation in a small vehicle affects the physiological state and subsequent water consumption in goats. Anim Sci J 2008. [DOI: 10.1111/j.1740-0929.2008.00559.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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2
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Coiro V, Saccani-Jotti G, Rubino P, Manfredi G, Vacca P, Volta E, Chiodera P. Oxytocin inhibits the stimulatory effect of ghrelin on circulating neuropeptide Y levels in humans. J Neural Transm (Vienna) 2008; 115:1265-7. [PMID: 18461271 DOI: 10.1007/s00702-008-0057-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 04/20/2008] [Indexed: 11/30/2022]
Abstract
UNLABELLED Oxytocin (OT) effect on ghrelin-stimulated neuropeptide Y (NPY) secretion was evaluated in 12 normal men. TESTS ghrelin (1 microg/kg B.W. as an intravenous bolus); OT (2 mIU/min infusion); ghrelin plus OT; normal saline. Plasma NPY did not change during saline or OT infusions, whereas it showed a significant 29% increase vs baseline at 15 min after ghrelin injection. When OT was present, ghrelin-induced NPY increment was completely abolished. Results show that oxytocin modulates the NPY response to ghrelin, whereas it is unable to produce direct inhibitions of basal circulating NPY levels.
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Affiliation(s)
- Vittorio Coiro
- Department of Internal Medicine and Biomedical Sciences, University of Parma, Via A. Gramsci, 14-43100 Parma, Italy.
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3
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Abstract
An integrated hypothesis for explaining eating behavior must consider the organism as a whole, the multiple brain neurotransmitters and structures involved, and the diverse variables that have impact on the expression of the behavior. In this review, we will examine a variety of brain monoamines and neuropeptides, in terms of their impact on eating, and also relate these neurochemical systems to peripheral autonomic and endocrine functions. We will propose how these central and peripheral systems may interact under normal and generally stable conditions, as well as how they may help to maintain energy or nutritional homeostasis under stressful conditions, in particular, food deprivation.
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4
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Affiliation(s)
- Stephen C Woods
- Department of Psychiatry, University of Cincinnati, 2170 East Galbraith Road, Cincinnati, OH 45237, USA.
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AOYAMA M, NEGISHI A, ABE A, MAEJIMA Y, SUGITA S. Sex differences in stress responses to transportation in goats: Effects of gonadal hormones. Anim Sci J 2003. [DOI: 10.1046/j.1344-3941.2003.00146.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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6
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7
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Bittencourt JC, Vaughan J, Arias C, Rissman RA, Vale WW, Sawchenko PE. Urocortin Expression in Rat Brain: Evidence Against a Pervasive Relationship of Urocortin-Containing Projections With Targets Bearing Type 2 CRF Receptors. J Comp Neurol 1999. [DOI: 10.1002/(sici)1096-9861(19991220)415:3<285::aid-cne1>3.0.co;2-0] [Citation(s) in RCA: 277] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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8
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Abstract
Leptin is a satiety factor which acts within the hypothalamus to decrease the levels of several neuropeptides stimulating food intake (among them, neuropeptide Y [NPY]), while increasing those that inhibit food intake. These effects of leptin bring about decreased body weight. In vivo, leptin potentiates basal and insulin-stimulated glucose utilization, presumably its oxidation, and decreases fat storage. Leptin increases sympathetic-mediated energy dissipation, and the expression of uncoupling proteins-1, -2, and -3. In peripheral tissues (muscles, adipose, others), leptin decreases triglyceride content by increasing fatty acid oxidation, decreasing the activity/expression of esterification and lipogenic enzymes, and favoring lipolysis. It decreases the lipogenic activity of insulin. Ultimately, leptin depletes fat stores and promotes leanness. NPY, taken as one example of what an orexigenic agent may produce, increases food intake and body weight. It favors fat storage in adipose tissue by stimulating lipogenic activity. It decreases glucose utilization by muscles, making more glucose carbon available for lipogenesis. Effects of NPY result from vagus nerve-mediated hyperinsulinemia and overactivity of the hypothalamo-pituitary-adrenal axis. Thus, NPY favors fat stores, and ultimately obesity. Glucocorticoids are necessary for NPY effects to occur, because central administration of the neuropeptide in adrenalectomized animals is ineffective. Glucocorticoids also have genuine effects when administered centrally to normal rats. They increase the hypothalamic content of NPY and decrease that of CRH. This double neuro-peptidic change stimulates food intake, insulin output, adipose tissue storage ability, decreases the expression of uncoupling proteins-1 and -3, and increases body weight. Body weight homeostasis appears to require a finely tuned regulation of both leptin and glucocorticoids, with their respective opposite effects.
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Affiliation(s)
- F Rohner-Jeanrenaud
- Laboratoires de Recherches Métaboliques, Geneva University School of Medicine, Switzerland.
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9
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Guan XM, Yu H, Van der Ploeg LH. Evidence of altered hypothalamic pro-opiomelanocortin/ neuropeptide Y mRNA expression in tubby mice. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 59:273-9. [PMID: 9729427 DOI: 10.1016/s0169-328x(98)00150-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The tubby mouse is characterized by an autosomal recessive mutation which results in the development of maturity-onset obesity and sensorineural hearing loss and retinal degeneration. Although the tubby mutation which leads to a splicing defect of the tub gene has been identified recently, the mechanism by which it causes the obesity syndrome has not been established. In this study, the potential dysfunction of several hypothalamic neuroendocrine pathways involved in the central regulation of energy metabolism was investigated in tubby mice. In comparison with the wild-type controls, a significant reduction (20%) of pro-opiomelanocortin (POMC) mRNA expression was observed in the arcuate nucleus (ARC) of the mature, obese but not in the juvenile, non-obese tubby mice. Similarly, an age and body mass-dependent induction (about 30-fold) of neuropeptide Y (NPY) mRNA was observed in the dorsomedial (DMH) and ventromedial (VMH) hypothalamic nuclei of the tubby mice. However, NPY mRNA in the ARC was decreased by approximately 30 to 40% in both juvenile and mature tubby mice. The hypothalamic expression patterns of corticotropin releasing hormone (CRH) and the long form leptin receptor (OB-Rb) were not significantly altered in the mutant mice. These results suggest that the altered hypothalamic POMC and/or NPY functions may be important contributing factors for the development of obesity in this animal model.
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Affiliation(s)
- X M Guan
- Department of Genetics and Molecular Biology, Merck Research Laboratories, P.O. Box 2000, Rahway, NJ 07065, USA.
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10
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Sanchez M, Baker BI, Celis M. Melanin-concentrating hormone (MCH) antagonizes the effects of alpha-MSH and neuropeptide E-I on grooming and locomotor activities in the rat. Peptides 1997; 18:393-6. [PMID: 9145426 DOI: 10.1016/s0196-9781(96)00327-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The intraventricular (i.c.v.) administration of the neuropeptide melanocyte stimulating hormone (alpha-MSH) is known to elicit a series of behaviors in the rat which include excessive grooming and other motor activities. In bony fish, the pigmentary effects of alpha-MSH can be antagonized by the neuropeptide melanin-concentrating hormone (MCH). We therefore examined whether MCH or its sister peptide neuro-peptide E-I (NEI), derived from the same precursor molecule, would modulate the effect of alpha-MSH on grooming and motor activity in the rat, or perhaps elicit some responses of their own. Rats were injected i.c.v. with either artificial cerebrospinal fluid, alpha-MSH, MCH, NEI, or with two peptides together, and behavioral responses were monitored over the next 65 min. The i.c.v. injection of 1 microgram MSH significantly enhanced grooming behavior. NEI at the same dose increased grooming, rearing, and locomotor activities. MCH alone had no behavioral effects but it annulled the behavioral responses induced by either alpha-MSH or NEI. alpha-MSH also antagonized the locomotor and rearing behavior induced by NEI. The physiological significance of these observations is discussed.
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Affiliation(s)
- M Sanchez
- Department of Pharmacology, Facultad de Ciencias Quimias, Universidad Nacional de Cordoba, Ciencias Quimicas, Cordoba, Argentina
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11
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Sienkiewicz W, Majewski M, Kaleczyc J, Lakomy M. Distribution of catecholamine-synthesizing enzymes and some neuropeptides in the median eminence-arcuate nucleus complex (MEARC) of the immature female pig. Acta Histochem 1996; 98:419-34. [PMID: 8960306 DOI: 10.1016/s0065-1281(96)80009-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The presence of the catecholamine-synthesizing enzymes tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (D beta H) and some neuropeptides, including neuropeptide Y (NPY), Leu5-enkephalin (LENK), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL) and somatostatin (SOM) was investigated in nerve fibres and perikarya of the median eminence-arcuate nucleus complex (MEARC) of the sexually immature female pigs by means of the immunohistochemical avidin-biotin complex method. Although immunoreactivities to all the studied substances were found in nerve fibres of the porcine MEARC, there were differences in the distribution and density of particular subsets of nerve fibres within the complex. While loose D beta H-immunoreactive (D beta H-IR) and dense TH-, NPY- and VIP-IR nerve meshworks occurred predominantly in the internal layer of the MEARC, nerve fibres immunoreactive to TH, CGRP, SOM, SP and LENK were more numerous in the external than in the internal layer of the median eminence (ME). Numerous TH-, D beta H-, NPY-, VIP-, SP- and CGRP-IR perivascular nerve fibres were also observed within both layers of the median eminence. There were also differences in the distribution of a particular subset of neurons within the porcine MEARC: NPY-, VIP-, GAL-, SP- and TH-IR (but not D beta H-IR) perikarya were found in the arcuate nucleus, while in the median eminence only subpopulations of NPY-, VIP and GAL-IR neurons were observed.
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Affiliation(s)
- W Sienkiewicz
- Department of Animal Anatomy, Faculty of Veterinary Medicine, Agricultural and Technical University of Olsztyn, Poland
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12
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Wan RQ, Wiegant VM, de Jong W, de Wied D. Alterations of beta-endorphin-like immunoreactivity in CSF following behavioral training using a passive avoidance procedure. Psychoneuroendocrinology 1996; 21:503-13. [PMID: 8983087 DOI: 10.1016/s0306-4530(96)00013-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The central opioid system may have an important influence on memory processes. In view of this, the concentration of beta-endorphin-like immunoreactivity (beta-ELIR) in cerebrospinal fluid (CSF) was measured by a radioimmunoassay in rats trained in a passive avoidance procedure. The beta-ELIR in CSF was examined immediately, 2, 5, 10, and 30 min after the learning trial in which rats were exposed to footshock (0, 0.25, or 1.0 mA for 3 s). Avoidance latency and beta-ELIR in CSF were examined 24 and 120 h after the learning trial. The beta-ELIR in CSF was increased at 5 min after the learning trial in rats exposed to footshock of 0.25 mA. The beta-ELIR in CSF was elevated at 5 and 10 min, followed by a significant decrease at 30 min after the learning trial in rats exposed to a footshock of 1.0 mA. Thus, although an increase in beta-ELIR in CSF was not, the duration of the increase was, related to the shock intensity. Interestingly, a decrease followed the increase in beta-ELIR in CSF which was significant only in rats exposed to the high shock intensity. Avoidance latencies were enhanced in a shock intensity-dependent manner at both 24 and 120 h retention tests. No change in beta-ELIR in CSF was found during retention trials. The results suggest that behavioral manipulations alter beta-ELIR in CSF. An increase in beta-ELIR in CSF may be highly associated with stressful and emotional responses during behavioral training.
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Affiliation(s)
- R Q Wan
- Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Utrecht, The Netherlands
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13
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Brambilla F, Brunetta M, Draisci A, Peirone A, Perna G, Sacerdote P, Manfredi B, Panerai AE. T-lymphocyte concentrations of cholecystokinin-8 and beta-endorphin in eating disorders: II. Bulimia nervosa. Psychiatry Res 1995; 59:51-6. [PMID: 8771220 DOI: 10.1016/0165-1781(95)02674-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Concentrations of cholecystokinin-8 (CCK-8) and beta-endorphin (beta-EP) in T-lymphocytes of 26 women with bulimia nervosa (BN) and in 26 age- and sex-matched healthy comparison subjects were measured. Ten patients were then treated with 300 mg/day of fluvoxamine, p.o., and five patients were treated with 300 mg/day of amineptine, p.o., for 4 months. Concentrations of the two peptides were measured again after 1, 2, and 4 months of therapy. Basal CCK-8 values were significantly lower in patients than in healthy subjects. During fluvoxamine therapy, CCK-8 values increased, reaching normal levels by month 4 of treatment. No such increase occurred during amineptine therapy. Baseline beta-EP values were normal in the bulimic patients but had declined by month 4 of fluvoxamine therapy.
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Affiliation(s)
- F Brambilla
- Psychoneuroendocrine Center, Ospedale Pini, Milan, Italy
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14
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Brambilla F, Brunetta M, Peirone A, Perna G, Sacerdote P, Manfredi B, Panerai AE. T-lymphocyte cholecystokinin-8 and beta-endorphin concentrations in eating disorders: I. Anorexia nervosa. Psychiatry Res 1995; 59:43-50. [PMID: 8771219 DOI: 10.1016/0165-1781(95)02664-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Baseline concentrations of cholecystokinin-8 (CCK-8) and beta-endorphin (beta-EP) were measured in T-lymphocytes from 33 restricting patients with anorexia nervosa (AN-R), 23 binging/purging patients with anorexia nervosa (AN-BP), and 24 healthy volunteers. CCK-8 basal values were significantly lower and beta-EP values significantly higher in AN-R and AN-BP patients than in normal volunteers. Levels of the peptides were measured three more times during a 4-month combined cognitive-behavioral/psychopharmacological treatment (nortriptyline or fluoxetine in AN-R, fluoxetine or amineptine in AN-BP). CCK-8 values fluctuated (nonsignificantly) during each treatment, while beta-EP values decreased (to a significant degree only in fluoxetine-treated AN-R patients).
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Affiliation(s)
- F Brambilla
- Centro di Psiconeuroendocrinologia, Ospedale Psichiatrico Pini, Milan, Italy
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15
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Grignaschi G, Sironi F, Samanin R. The 5-HT1B receptor mediates the effect of d-fenfluramine on eating caused by intra-hypothalamic injection of neuropeptide Y. Eur J Pharmacol 1995; 274:221-4. [PMID: 7768274 DOI: 10.1016/0014-2999(94)00766-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
d-Fenfluramine (0.63 mg/kg i.p.), a serotonin (5-hydroxytryptamine, 5-HT) releaser and re-uptake inhibitor, reduced the eating caused by neuropeptide Y (235 pmol) injected into the paraventricular nucleus of the hypothalamus. The 5-HT1 and 5-HT2 receptor antagonist metergoline (1.0 and 2.0 mg/kg i.p.) and the 5-HT1A and 5-HT1B receptor antagonist (+/-)-cyanopindolol (3.0 and 8.0 mg/kg s.c.) significantly antagonized the effect of d-fenfluramine. The 5-HT2A and 5-HT2C receptor antagonist mesulergine (0.1 and 0.3 mg/kg s.c.) and the 5-HT2A receptor antagonist ketanserin (2.5 and 5.0 mg/kg i.p.) did not significantly modify the effect, nor did the 5-HT1A and 5-HT1B receptor antagonist (-)-propranolol (20-40 nmol), injected bilaterally into the paraventricular nucleus of the hypothalamus. The results suggest that d-fenfluramine reduces neuropeptide Y's hyperphagia by indirectly stimulating 5-HT1B receptors outside the paraventricular nucleus of the hypothalamus.
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Affiliation(s)
- G Grignaschi
- Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
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16
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Wiersma A, Baauw AD, Bohus B, Koolhaas JM. Behavioural activation produced by CRH but not alpha-helical CRH (CRH-receptor antagonist) when microinfused into the central nucleus of the amygdala under stress-free conditions. Psychoneuroendocrinology 1995; 20:423-32. [PMID: 8532825 DOI: 10.1016/0306-4530(94)00074-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The central nucleus of the amygdala (CeA) is known to be involved in the regulation of autonomic, neuroendocrine, and behavioural responses in stress situations. The CeA contains large numbers of corticotropin-releasing hormone (CRH)-containing cell bodies and terminals. In the present study we examined (by continuous behaviour observations) the effects of a high dose of CRH (150 ng) and two doses of the CRH-receptor antagonist (alpha-hCRH: 1.0 and 0.1 micrograms) after microinfusion into the CeA in freely moving male Wistar rats under stress-free conditions. In comparison with control, alpha-hCRH infusion did not cause any behavioural activation. In contrast CRH-infusion revealed a long-lasting increase in grooming and exploration with a concomitant decrease in behaviours specified as resting. These results indicate that the CRH system in the CeA does not seem to be activated in stress-free conditions, but its activation is of importance for active behavioural responses.
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Affiliation(s)
- A Wiersma
- Department of Animal Physiology, University of Groningen, Haren, The Netherlands
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17
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Kow LM, Mobbs CV, Pfaff DW. Roles of second-messenger systems and neuronal activity in the regulation of lordosis by neurotransmitters, neuropeptides, and estrogen: a review. Neurosci Biobehav Rev 1994; 18:251-68. [PMID: 7914686 DOI: 10.1016/0149-7634(94)90028-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Many neurotransmitters and neuropeptides can affect the rodent feminine sexual behavior, lordosis, when administered in the ventromedial hypothalamus (VMH), midbrain central gray (MCG), or other brain regions. A survey of the electrophysiological and biochemical actions of these neural agents revealed that there is a very consistent association between lordosis facilitation with both the activation of the phosphoinositide (PI) pathway and the excitation of VMH and MCG neurons. In contrast, lordosis inhibition is associated, less consistently, with alterations of the adenylate cyclase (AC) system and the inhibition of neuronal activity. The findings that lordosis could be facilitated by going beyond membrane receptors and directly activating the PI pathway, suggest that this second-messenger pathway is a common mediator for the lordosis-facilitating agents. Furthermore, as in the case of stimulating membrane receptors, direct activation of this common mediator also requires estrogen priming for lordosis facilitation. Therefore, it is likely that the PI pathway is modulated by estrogen in the permissive action of estrogen priming. Indeed, a literature review shows that estrogen can affect selective isozymes of key enzyme families of the PI pathway at various levels. Such selective modulations, at several levels, could easily alter the course of a PI cascade; thence, the eventual functional outcome. These findings prompt us to propose that estrogen enables lordosis to be facilitated by a selective modulation of the PI pathway.
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Affiliation(s)
- L M Kow
- Rockefeller University, Laboratory of Neurobiology and Behavior, New York, NY 10021
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18
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Chan MY, Tang F. Brain cholecystokinin octopeptide (CCK-8) concentrations: effect of tryptophan and other serotonergic agents. Neuropeptides 1994; 26:59-63. [PMID: 7512698 DOI: 10.1016/0143-4179(94)90094-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effects of 1-week drug treatment on the brain contents of neuropeptides were investigated. The cholecystokinin (CCK) concentrations in the hypothalamus were significantly decreased by tryptophan treatment but not by imipramine and cyproheptadine, which changed the serotonergic function. Proglumide, the CCK antagonist, induced in the hypothalamic and hippocampal-striatal areas an increase in CCK concentration, which was not reversed in the presence of tryptophan. Dynorphin and substance P(SP) concentrations were also modified by proglumide treatment.
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Affiliation(s)
- M Y Chan
- Department of Pharmacology, Faculty of Medicine, University of Hong Kong
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19
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Blundell JE, Greenough A. Pharmacological aspects of appetite: implications for the treatment of obesity. Biomed Pharmacother 1994; 48:119-25. [PMID: 7993976 DOI: 10.1016/0753-3322(94)90100-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The properties of an ideal weight-reducing drug would be to produce a sustained decrease in body fat, to oppose the recidivism in obese patients and to improve compliance to dietary requirements. More specifically the drug would have to decrease hunger, be active in the long term, preferably produce no tolerance or rebound effects, and prevent any decrease in basal metabolic rate. Moreover, the drug should reduce the intake of dietary fat which is now regarded as a major cause of weight gain (and regain) [14]. Can this be achieved? Can drug-induced appetite control be used to combat obesity? Some drugs have already demonstrated a capacity to adjust appetite so as to produce significant improvements in the pattern of eating and the control of body weight. What mechanisms are responsible for such an action and how can new drugs be developed so as to advance the pharmacological control of appetite?
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Affiliation(s)
- J E Blundell
- Department of Psychology, University of Leeds, UK
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20
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Wang ZP, Man SY, Tang F. Age-related changes in the contents of neuropeptides in the rat brain and pituitary. Neurobiol Aging 1993; 14:529-34. [PMID: 8295655 DOI: 10.1016/0197-4580(93)90035-a] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
beta-Endorphin, Leu-enkephalin, Met-enkephalin, substance P, somatostatin, and cholecystokinin were measured in the brain and the pituitary of male Sprague-Dawley rats aged 3 months, 12 months, and 22 months. beta-Endorphin, Met-enkephalin and Leu-enkephalin contents in the neurointermediate lobe, and the enkephalin levels in the anterior lobe of the pituitary increased with age. The increases in contents were both in the day and at night for beta-endorphin and Met-enkephalin. However, the increase for Leu-enkephalin content was in the day only. Hypothalamic beta-endorphin content decreased with age only in the day. beta-Endorphin and Leu-enkephalin contents in the brain stem, and Leu-enkephalin levels contents in the cortex decreased with age at night. Leu-enkephalin in the striatum decreased with age in the day. There was also an age-related decrease for somatostatin and substance P contents in the striatum and the hypothalamus in the day, and in cholecystokinin levels in the hippocampus, and the hypothalamus at night. It is concluded that there are age differences in neuropeptide levels, and that these changes may differ according to diurnal rhythms.
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Affiliation(s)
- Z P Wang
- Department of Physiology, Faculty of Medicine, University of Hong Kong
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21
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Richard D. Involvement of corticotropin-releasing factor in the control of food intake and energy expenditure. Ann N Y Acad Sci 1993; 697:155-72. [PMID: 8257008 DOI: 10.1111/j.1749-6632.1993.tb49930.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- D Richard
- Département de Physiologie, Faculté de Médecine, Université Laval, Québec, Canada
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22
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Abstract
Studies with dexfenfluramine, an anorectic agent which releases 5-hydroxytryptamine (5-HT) from nerve terminals and inhibits its reuptake, have considerably increased our knowledge of the role of 5-HT in feeding control. 5-HT1B receptors mediate the satiating effect of dexfenfluramine, whereas the mechanism by which 5-HT uptake inhibitors such as fluoxetine and sertraline cause anorexia is not clear. Anorexia induced by (+)-amphetamine, phentermine, diethylpropion and phenylpropanolamine seems to be the result of their ability to increase the release of noradrenaline and/or dopamine from nerve terminals and inhibit their reuptake or, in the case of phenylpropanolamine, to stimulate directly alpha 1-adrenoceptors. It has been suggested that beta- and alpha 1-adrenoceptors and D1 dopamine receptors are involved in their effect on food intake. The difficulties of extrapolation across species limit our knowledge of the mechanism of the anorectic action in humans. Significant advances in the treatment of feeding pathology will be linked to identifying new receptor types and subtypes for neurotransmitters and quantifying and modelling eating disorders such as binge-eating and food craving.
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Affiliation(s)
- R Samanin
- Mario Negri Institute of Pharmacological Research, Milano, Italy
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23
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Kirouac GJ, Ganguly PK. Cholecystokinin receptor density in the striatum of the spontaneously hypertensive rat. Brain Res 1993; 604:338-41. [PMID: 8457862 DOI: 10.1016/0006-8993(93)90387-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The possibility that cholecystokinin in the striatum may be involved in hypertension was investigated using in vitro receptor autoradiography. The binding density of 125I-Bolton Hunter labeled cholecystokinin octapeptide (125I-BH-CCK8) was determined using computer-assisted densitometry in the striatum of the spontaneously hypertensive rat (SHR) and its control the Wistar-Kyoto rat (WKY). A significant increase in 125I-BH-CCK8 binding density was found in the lateral part of the caudate-putamen of the SHR. In contrast, a significant decrease in 125I-BH-CCK8 binding density was found in the posteromedial nucleus accumbens of the SHR. These results indicate that CCK8 receptor density is altered in the striatum of the SHR and suggest a role for CCK8 receptors in the pathophysiology of hypertension.
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Affiliation(s)
- G J Kirouac
- Division of Cardiovascular Sciences, St. Boniface Hospital Research Centre, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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24
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Ranft U, Hennig A. [The regulation of feed intake and selection with special reference to poultry]. ARCHIV FUR TIERERNAHRUNG 1991; 41:563-81. [PMID: 1683223 DOI: 10.1080/17450399109428502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Feed intake is regulated in a dialogue between the animal and the feed, which is influenced by numerous factors. The hypothalamus has a central integrative function. Furthermore, caudal brain areas (medulla oblongata, pons) are of importance because these areas are relays of peripheral signals and gustatory afferents. All peripheral informations are integrated by various neurotransmitters and neurohormones. The function of this neuronal system is not exactly known yet. Sensorial informations, mechano-, chemo- and osmoreceptors of the gastrointestinal tract and gastrointestinal hormones are discussed as influences of the periphery. The physiological satiety function of cholecystokinin is questionable in poultry. Hepatic chemoreceptors, which are activated by various metabolites, influence the amount of feed ingested. The feed choice appears to be regulated by the same mechanisms. Our knowledge about the translation of peripheral signals into choice behaviour by changes of neurotransmitter systems is limited.
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Affiliation(s)
- U Ranft
- Universität Leipzig, Agrarwissenschaftliche Fakultät, Institut für Tierernährungschemie
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25
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Abstract
It is relatively easy to demonstrate drug-induced anorexia in animals, but the significance of-such suppression of eating is often doubtful. Of the many agents shown to be 'active' in animals, only a very few are genuine appetite suppressants with clinical potential. Drugs that increase central 5-HT levels, or that activate peripherally acting peptides, are currently among the most promising candidates. John Blundell advocates a systems approach to the study of appetite control. Drug-induced changes in feeding should be interpreted according to a system which involves behaviour, peripheral physiology and brain neural pathways. Appetite involves more than alterations of food intake; the concept should take into account changes in hunger, food preferences, responses to taste and changes in macronutrient preferences.
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Orosco M, Robert JJ, Rouch C, Jacquot C, Cohen Y. Reversal of a feeding-reward system by dexfenfluramine: neurochemical involvement. Physiol Behav 1990; 48:887-92. [PMID: 2087521 DOI: 10.1016/0031-9384(90)90244-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In addition to its anorectic properties, dexfenfluramine may inhibit some manifestations of feeding-related reward. We attempted to verify this effect by measuring paw-lick latency on the hot plate test in rats conditioned to expect a palatable food. The involvement of variations in beta-endorphinergic, dopaminergic and serotonergic systems was assessed. Despite an inherent effect of increasing paw-lick latency, dexfenfluramine (1.5 mg/kg IP) partly reversed the expectancy-induced increase in this latency. Saline-treated "expectant" rats displayed elevated plasma beta-endorphin levels and reduced hypothalamic 5-HIAA/5-HT and DOPAC/DA ratios. Only the decrease in the DOPAC/DA ratio was reversed by dexfenfluramine, suggesting an involvement of the dopaminergic system in this dexfenfluramine-sensitive reward system.
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Affiliation(s)
- M Orosco
- Laboratoire de Pharmacologie, URA-CNRS 594, Faculté de Pharmacie, Chatenay-Malabry, France
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28
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Zardetto-Smith AM, Gray TS. Organization of peptidergic and catecholaminergic efferents from the nucleus of the solitary tract to the rat amygdala. Brain Res Bull 1990; 25:875-87. [PMID: 1981174 DOI: 10.1016/0361-9230(90)90183-z] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Previous studies have focused on the role of the central nucleus of the amygdala (CeA) in cardiovascular and other amygdaloid functions. The combined retrograde tracing/immunohistochemical method was used to test for the presence of enkephalin, neurotensin, neuropeptide Y, and catecholamine neurons within the nucleus of the solitary tract that send efferents to the CeA. After injections of retrograde tracer into the CeA, retrogradely labeled neurons were observed within the caudal, medial nucleus of the solitary tract. Most CeA-projecting neurons were located ipsilaterally within the medial nucleus of the solitary tract at the level of the area postrema. Retrogradely labeled enkephalin- and neurotensin-immunoreactive neurons were found within the medial nucleus of the solitary tract at this level, while retrogradely labeled neuropeptide Y-immunoreactive neurons were found within the medial nucleus of the solitary tract rostral to the area postrema. About 60-74% of CeA-projecting cells were also immunoreactive for tyrosine hydroxylase. Approximately 9% of retrogradely neurons were phenylethanolamine-N-methyltransferase immunoreactive. The results provide evidence that within the nucleus of the solitary tract, peptidergic CeA-projecting neurons have a topographic distribution. In addition, noradrenergic neurons within the A2 group, rather than adrenergic neurons of the C2 group, provide the bulk of catecholaminergic input to the CeA from the nucleus of the solitary tract. Cell counts indicate that each of these peptides may be colocalized (to varying extents) within catecholamine-producing neurons. Also the catecholaminergic and enkephalinergic contribution to the ascending pathway from the nucleus of the solitary tract to the CeA distinguishes it neurochemically from the descending pathway. Thus, although there are afferent and efferent connections between the nucleus of the solitary tract and CeA, their peptidergic/neurotransmitter connections are not necessarily reciprocal. Input from nucleus of the solitary tract peptidergic and catecholaminergic neurons to the CeA may be important in the etiology of a number of pathophysiological conditions including hypertension, gastric ulcers, and schizophrenia.
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Affiliation(s)
- A M Zardetto-Smith
- Department of Cell Biology, Neurobiology and Anatomy Loyola Stritch School of Medicine, Maywood, IL 60153
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29
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Rasori E, Poggioli R, Bertolini A. Influence of bestatin on feeding behavior. Pharmacol Res 1990; 22 Suppl 3:107-8. [PMID: 2097619 DOI: 10.1016/s1043-6618(09)80052-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- E Rasori
- Institute of Pharmacology, University of Modena, Italy
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30
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31
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Riche D, De Pommery J, Menetrey D. Neuropeptides and catecholamines in efferent projections of the nuclei of the solitary tract in the rat. J Comp Neurol 1990; 293:399-424. [PMID: 1969868 DOI: 10.1002/cne.902930306] [Citation(s) in RCA: 191] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study focuses on the involvement of catecholamines and nine different peptides in efferents of the nucleus of the solitary tract to the central nucleus of the amygdala, the bed nucleus of the stria terminalis, and different parabrachial and hypothalamic nuclei in the rat. A double-labeling technique was used that combines a protein-gold complex as the retrograde tracer with immunohistochemistry. Catecholaminergic projection neurons were the most numerous type observed and projected mainly ipsilaterally to all targets studied. Most projections arose from areas overlying the dorsal motor nucleus, mainly the medial nucleus. Neurons synthesizing somatostatin, met-enkephalin-Arg-Gly-Leu, dynorphin B, neuropeptide Y, and neurotensin projected to all structures examined. Somatostatin and enkephalin immunoreactive projection cells were the most numerous. They were located in close proximity to each other, including all subnuclei immediately surrounding the solitary tract, bilaterally. Most dynorphin and neuropeptide Y immunoreactive projection cells were found rostral to that of enkephalinergic and somatostatinergic projections, and mainly in the ipsilateral medial nucleus. Neurotensinergic projections were sparse and from dorsal and dorsolateral nuclei. Substance P and cholecystokinin contribute to parabrachial afferents. The location of substance P immunoreactive projection cells closely resembled that of enkephalinergic and somatostatinergic projections. Projecting cholecystokinin immunoreactive cells were observed in dorsolateral nucleus. Bombesin immunoreactive cells in dorsal nucleus projected to either the parabrachial or hypothalamic nuclei. No vasoactive intestinal polypeptide-containing cells were detected. Thus, most catecholaminergic and neuropeptidergic efferents originated from different populations of cells. It is proposed that catecholaminergic neurons constitute the bulk of solitary efferents and that they may contribute to autonomic neurotransmission. Peptidergic neurons mainly form other subgroups of projections and may play a role in modulating the physiological state of the target nuclei.
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Affiliation(s)
- D Riche
- CNRS, Laboratoire de Physiologie Nerveuse, Gif-sur-Yvette, France
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32
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Shulkes A, Lewis SJ, Jarrott B. Strain differences in central nervous system concentrations of cholecystokinin between normotensive Wistar Kyoto (WKY) and spontaneously hypertensive (SH) rats. Neuropeptides 1989; 14:59-64. [PMID: 2779758 DOI: 10.1016/0143-4179(89)90035-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The regional brain and spinal cord concentrations of cholecystokinin-octapeptide (CCK-8) were measured in age-matched normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SH) rats. The relative order of distribution of CCK-8 in the WKY strain was hippocampus (20.5 +/- 1.3 pmol/g) greater than cortex greater than striatum = hypothalamus greater than midbrain = thalamus greater than spinal cord greater than medulla oblongata/pons (MO/P, 1.6 +/- 0.2 pmol/g) whereas in the SH strain this order was hippocampus (12.9 +/- 0.8 pmol/g) greater than cortex = striatum greater than hypothalamus greater than midbrain greater than thalamus = spinal cord greater than MO/P (1.4 +/- 0.2 pmol/g). The concentrations of CCK-8 in the cerebellum were at the level of assay sensitivity (0.5 pmol/g in both strains). In comparison to the WKY rats, the SH strain had significantly lower levels of CCK-8 in the hippocampus (-37%), cortex (-28%), spinal cord (-23%) and pituitary (-57%). The lowered levels of CCK-8 in the brain of the SH rat may be causally related to, or result from, the cardiovascular, behavioural or morphological abnormalities of this strain.
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Affiliation(s)
- A Shulkes
- Department of Surgery and Clinical Pharmacology, Austin Hospital, Heidelberg, Victoria, Australia
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33
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Snapir N, Robinzon B. Role of the basomedial hypothalamus in regulation of adiposity, food intake, and reproductive traits in the domestic fowl. Poult Sci 1989; 68:948-57. [PMID: 2674924 DOI: 10.3382/ps.0680948] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Bilateral basomedial hypothalamic (BMH) electrolytic lesions in White Leghorn cockerels produced six main physiological categories characterized by typical sets of symptoms: 1) functional castration (FC); hyperphagia, obesity, occasional diabetes insipidus, involuted adenohypophysis, dwarfism, atrophied comb and testes, reduced hematocrit, reduced plasma testosterone and thyroid activity, involuted thymus and adrenal cortex and elevated liver fat and plasma triglycerides and free fatty acids. The FC birds demonstrated defective immune response for the first 12 to 16 wk post-surgery. 2) functional castration with large comb (FCLC); hyperphagia, obesity, transient diabetes insipidus, slight diminution of adenohypophy-seal weight with marked reduction in basophilic cell population, fully atrophied testes but only slight reduction in comb size and hematocrit, plasma testosterone levels between those found in the first category and the control. 3) obese with normal testes (ONT); hyperphagia, obesity, high level of plasma lipids, normal histological organization of the adenohypophysis, normal testes, semen production and comb size. The next three categories exhibited physiological syndromes identical to the former three categories except for food intake, which operationally could be defined as normal. A marked difference among the BMH-lesioned birds was found in sexual behavior when the FC birds completely lost their libido. None of the replacement therapy regimens caused complete rehabilitation from adiposity or restoration of reproductive traits. Lipoprotein lipase activity increased at an early stage postlesioning and preceeded the development of hyperphagia. Placement of BMH lesions in newly hatched chicks resulted in marked dwarfism and obesity without hyperphagia. The BMH-lesioned heavy breed White Rock cockerels exhibited a lesser degree of adiposity than the light White Leghorn birds. Removal of the olfactory bulbs and destruction of the septal area resulted in increased thyroid activity, with secondary hyperphagia without obesity. In a short-term study, administration of sodium pentobarbital to the BMH area resulted in increased feeding. Conversely, glucose administration to the same area suppressed feeding in satiated but not in food-deprived chickens.
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Affiliation(s)
- N Snapir
- Department of Animal Science, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel
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34
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Abstract
The behavioral effects of bombesin in 5-, 10- and 20-day-old rat pups have been investigated and the peptide was found to induce scratching (1, 10 mg/kg IP) and grooming (10 mg/kg IP) as early as 5 days after birth. Bombesin did not produce any other overt activities in the developing pups in doses of up to 10 mg/kg, however, lower doses of the peptide (0.1, 1 mg/kg IP) reduced intake of a wet mash diet in deprived 15-day-old rat pups resulting in significant decreases in body weight compared with control animals. These behavioral responses agree with the well-documented effects of bombesin in adult rats and are also in accordance with results from biochemical studies which have shown the existence of receptors for bombesin-like peptides in the rat central nervous system from an early age.
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Affiliation(s)
- H C Jackson
- Department of Biochemistry, University of Surrey, Guildford, UK
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35
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Okayama T, Kubota Y, Kito S, Funaki H, Shimada S, Takagi H, Inagaki S. A light and electron microscopic study of calcitonin gene-related peptide in the rat caudate putamen. Brain Res Bull 1989; 22:657-63. [PMID: 2786738 DOI: 10.1016/0361-9230(89)90086-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Calcitonin gene-related peptide (CGRP)-like immunoreactive (CGRP-IR) structures have been studied in the rat caudate putamen using avidin-biotin peroxidase immunohistochemistry. Immunoreactivity was found in the axons of this nucleus but not in the perikarya. CGRP-IR fibers were most densely concentrated along the ventral border and in the caudal portion of the rat caudate putamen. CGRP-IR fibers were sparsely distributed throughout the rest of this nucleus. Almost all immunoreactive boutons which contained small clear vesicles had formed asymmetrical synapses. Postsynaptic targets included dendritic spines and shafts. Asymmetrical synapses in the caudate putamen are supposed to be extrinsic in origin. These observations, together with the results of other investigations, suggest that CGRP-IR boutons form synapses with spiny striatal neurons, which, most likely, are medium-sized spiny projecting neurons. Moreover, evidence indicates that these boutons are of extrinsic origin.
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Affiliation(s)
- T Okayama
- Third Department of Internal Medicine, Hiroshima University School of Medicine, Japan
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36
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Abstract
Oxytocin, whether administered intraperitoneally (IP) (375-6,000 micrograms/kg) or intracerebroventricularly (ICV) (1-10 micrograms/rat), dose-dependently reduced food consumption and time spent eating and increased the latency to the first meal in rats fasted for 21 hr. Pretreatment with the oxytocin antagonist d(CH2)5Tyr(Me)-[Orn8]vasotocin (ICV 10 micrograms/rat) completely prevented the feeding inhibitory effect of an equal dose of ICV oxytocin, and per se increased food intake. Our data further support the hypothesis that oxytocin plays the role of neurotransmitter or neuromodulator in the CNS, and suggest that its involvement in a number of homeostatic systems may include appetite control.
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Affiliation(s)
- R Arletti
- Institute of Pharmacology, University of Modena, Italy
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37
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Inagaki S, Kubota Y, Shimada S, Tohyama M, Kito S, MacIntyre I, Takagi H. Ontogeny of calcitonin gene-related peptide-immunoreactive structures in the rat forebrain and diencephalon. Brain Res 1988; 471:235-48. [PMID: 3263173 DOI: 10.1016/0165-3806(88)90102-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ontogeny of the calcitonin gene-related peptide (CGRP)-containing structures was investigated in the forebrain and diencephalon of the rat by means of indirect immunofluorescence. CGRP-like immunoreactive (CGRP-IR) fibers first appeared at gestational day 18 (E18) in the primordia of the bed nucleus of the stria terminalis, central amygdaloid nucleus and posterolateral portion of the lateral hypothalamic nucleus. CGRP-IR fibers gradually increased in immunoreactivity and in number in these nuclei toward birth. A pronounced increase of CGRP-like immunoreactive fibers was found after birth in these nuclei and made very dense plexuses of fibers in adult animals. A few CGRP-IR fibers first appeared at the perinatal stage in the lateral septum, the most caudal portion of the caudate-putamen, and ventromedial and ventroposterior thalamic nuclei. Then the immunoreactive fibers increased and dense plexuses were present in these brain areas of the adult. A small number of immunoreactive fibers appeared at postnatal day 4-7 (P4-7) in the caudal insular cortex and ventromedial hypothalamic nucleus. A significant number of fibers was present in these areas of the adult. On the other hand, CGRP-like immunoreactivity in cell bodies was first detected with faint immunofluorescence at P4 in the anteromedial parts of the lateral hypothalamic area and ventromedial and ventroposterior thalamic nuclei. Thereafter CGRP-IR cells increased in immunoreactivity, and a significant number of cells was noted in these nuclei of the adult. In addition, CGRP-IR cells are identified in the medial amygdaloid nucleus, and medial preoptic area at P14. In conclusion, in the forebrain and diencephalon (1) CGRP-like immunoreactivity appears in fibers earlier than in cell bodies, suggesting that at least some of immunoreactive fibers originate from the lower brainstem, and (2) high density of CGRP-IR structures present in the brain at embryonic and early postnatal stages may indicate that CGRP could be an important factor involved in the developmental organization of the central nervous system.
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Affiliation(s)
- S Inagaki
- First Department of Anatomy, Osaka City University Medical School, Japan
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38
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Dafny N, Gillman MA, Lichtigfeld FJ. Cholecystokinin: induced suppression of feeding in fed, fasting and hypothalamic island rats. Brain Res Bull 1988; 21:225-31. [PMID: 3191409 DOI: 10.1016/0361-9230(88)90235-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Experiments were undertaken to examine the involvement of CCK in the regulation of feeding behavior. The results indicate that 1) intact normal animals exhibited rhythmic circadian feeding behavior, with onset of feedings starting about two hr prior to dark period and continuing until 1 to 2 hr prior to the light period; 2) food deprivation and surgical isolation of the hypothalamus after this pattern of feeding behavior, to the point that animals spend more time eating with no identifiable pattern; 3) administration of CCK to either fed, fasted or hypothalamic island animals has a profound dose related effect on suppressing feeding behavior and in modifying the eating pattern over 24 hr. A possible involvement of CCK with the opiate system in controlling feeding behavior is discussed.
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Affiliation(s)
- N Dafny
- University of Texas Medical School, Department of Neurobiology and Anatomy, Houston 77225
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39
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Vaccarino FJ, Hayward M. Microinjections of growth hormone-releasing factor into the medial preoptic area/suprachiasmatic nucleus region of the hypothalamus stimulate food intake in rats. REGULATORY PEPTIDES 1988; 21:21-8. [PMID: 3134673 DOI: 10.1016/0167-0115(88)90087-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The role of the suprachiasmatic nucleus/medial preoptic area region of the hypothalamus in the expression of rat hypothalamic growth hormone-releasing factor-induced feeding in the rat was examined. Rats were tested for their 90-min food intake following microinjections of growth hormone-releasing factor (0.0, 0.01, 0.1 or 1.0 pmol) aimed at the suprachiasmatic nucleus/medial preoptic area region. It was found that growth hormone-releasing factor dose-dependently stimulated food intake with the 1.0 pmol dose being the most effective, increasing food intake by approximately 200%. Injections outside the suprachiasmatic nucleus/medial preoptic area region were ineffective. These data are taken to suggest that the suprachiasmatic nucleus/medial preoptic area region of the hypothalamus is important for the central stimulatory effects of growth hormone-releasing factor on feeding.
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Affiliation(s)
- F J Vaccarino
- Department of Psychology, University of Toronto, Ont., Canada
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40
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Martel JC, St-Pierre S, Quirion R. Comparative distribution of neuropeptide Y immunoreactivity and receptor autoradiography in rat forebrain. Peptides 1988; 9 Suppl 1:15-20. [PMID: 2856639 DOI: 10.1016/0196-9781(88)90217-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The distributions of neuropeptide Y (NPY) and NPY receptors in rat brain have been compared. High densities of NPY-like fibers and terminals are present in the hypothalamus and the endopiriform nucleus with corresponding low densities of NPY receptor binding sites. Conversely, low densities of fibers and terminals are observed in the thalamus, stria terminalis and hippocampus with corresponding high densities of binding sites. Various hypotheses are discussed to explain those apparent mismatches including the existence of other classes of receptors and possible paracrine actions of NPY-like peptides in the brain.
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Affiliation(s)
- J C Martel
- Douglas Hospital Research Centre, Verdun, Québec, Canada
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41
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Abstract
Weight loss and anorexia occur commonly in the elderly. While in many cases the anorexia can be attributed to associated disease processes, it does appear that a true anorexia of aging exists. Animal studies have suggested that older rodents have an excessive satiety effect of cholecystokinin and a decreased opioid feeding drive. Other older persons develop anorexia in association with depression. In these subjects, excess corticotropin-releasing factor may be the neurotransmitter involved in the pathogenesis of the anorexia. In Alzheimer's disease, decreases in norepinephrine and neuropeptide Y may be involved in the anorexia seen in the these patients.
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Affiliation(s)
- J E Morley
- Geriatric Research, Education and Clinical Center, Sepulveda VA Medical Center, CA 91343
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42
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Steffens AB, Scheurink AJ, Luiten PG, Bohus B. Hypothalamic food intake regulating areas are involved in the homeostasis of blood glucose and plasma FFA levels. Physiol Behav 1988; 44:581-9. [PMID: 3070585 DOI: 10.1016/0031-9384(88)90322-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The hypothalamus fulfills multiple functions, e.g., integration of food and water ingestion, various forms of social behavior and physiological neuroendocrine activities. Hypothalamic areas, particularly the ventromedial, lateral and paraventricular areas (VMH, LHA and PVN respectively), that contribute to the regulation of food intake are also involved in the regulation of blood glucose and plasma free fatty acid (FFA) levels. This regulation is controlled both directly via neural pathways and indirectly by hormones, e.g., insulin, glucagon, norepinephrine (NE) and epinephrine (E). A description is presented of the intrahypothalamic connections and the pathways between the hypothalamus and the motor areas of both the sympathetic system in the spinal cord (the intermediolateral column IML) and the parasympathetic system in the brainstem (the dorsal motornucleus of the vagus and the nucleus ambiguus). Noradrenergic stimulation of the LHA, VMH and PVN can alter blood glucose, plasma FFA and insulin levels independently of each other, e.g., noradrenergic stimulation of the VMH leads to an increase of insulin, glucose and FFA. Exercise induced increases of glucose are suppressed by alpha-adrenergic blockade of the LHA, VMH and PVN. Alpha-adrenergic blockade of the VMH during exercise causes an exaggerated increase of plasma FFA whereas alpha-blockade of both the LHA and PVN does not change the normal exercise induced increase of plasma FFA. The apparent contradiction that both adrenergic stimulation and adrenergic blockade of the VMH result in an increase in FFA may be explained by assuming postsynaptic alpha- and beta-adrenergic receptors in the VMH controlling glucose and FFA release respectively and FFA release and presynaptic inhibitory alpha-adrenergic receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A B Steffens
- Department of Animal Physiology, Haren, The Netherlands
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43
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Stoynev AG, Ikonomov OC. Circadian regulation of feeding in rats: suprachiasmatic versus ventromedial hypothalamic nuclei. Appetite 1987; 9:217-29. [PMID: 3324965 DOI: 10.1016/s0195-6663(87)80015-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The role of the suprachiasmatic nuclei as a major component of a specific circadian system controlling feeding periodicity is reviewed. Evidence is presented supporting the assumption that the ventromedial hypothalamus and the suprachiasmatic nucleus may act as a constant (tonic) regulator and a circadian modulator respectively of feeding in rats. It is concluded that a specific circadian system differing from the metabolic control mechanism superimposes the circadian periodicity of feeding. A model is put forward for the possible functional relationships between circadian and metabolic (homeostatic) control mechanisms of feeding in rats.
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Affiliation(s)
- A G Stoynev
- Department of Physiology, Medical Academy, Sofia, Bulgaria
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44
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45
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Steinman JL, Fujikawa DG, Wasterlain CG, Cherkin A, Morley JE. The effects of adrenergic, opioid and pancreatic polypeptidergic compounds on feeding and other behaviors in neonatal leghorn chicks. Peptides 1987; 8:585-92. [PMID: 2888097 DOI: 10.1016/0196-9781(87)90029-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The present study examined the effects of intracerebral (IC) administration of pancreatic polypeptide (PP), neuropeptide Y (NPY), norepinephrine (NE), dynorphin and naloxone on food intake in 2-day-old Leghorn chicks. Of the compounds studied, only PP (20 micrograms) and naloxone (10 and 20 micrograms) elevated food intake significantly as compared to saline injections. NPY, a potent orexigenic agent in mammals, did not elevate consumption significantly in a dose-related fashion. This latter finding was attributed to the occurrence of tonic-clonic convulsions following NPY administration. However, for those chicks which did not exhibit behavioral convulsions, food intake appeared to be elevated by 1, 5 and 10 micrograms of NPY. Similarly, NE did not elevate food intake but instead induced sedation and narcolepsy, a behavioral response which could be distinguished from the convulsions observed after NPY. In a separate group of chicks, the effect of NPY on cortical activity was examined. Bipolar electrodes were used to record EEG activity before and after IC injections of saline, NPY or NE. The behavioral convulsions induced by NPY corresponded with an increase in high amplitude sharp-wave activity, which persisted for up to 30 min post-injection. Collectively, these results suggest that the neurochemical substrates for feeding in 2-day-old Leghorn chicks are distinct from those underlying food intake in adult mammals.
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46
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Kuroki T, Matsumoto T, Hirano M, Kagoshima H, Yao H, Uchimura H, Nakamura K, Nakahara T. Long-lasting effect of systemically administrated caerulein on monoaminergic neuronal pathways in rat brain. Neuropeptides 1987; 9:169-76. [PMID: 2437491 DOI: 10.1016/0143-4179(87)90055-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The effect of systemically administrated cholecystokinin analog, caerulein, on monoaminergic neurons was examined in discrete regions of rat brain. A single injection of caerulein (400 micrograms/kg, i.p.) significantly elevated 5-hydroxyindoleacetic acid (5HIAA) levels in the prefrontal cortex lateral field, nucleus accumbens, tuberculum olfactorium and striatum after 2 hours, together with a significant increase in striatal serotonin (5HT). Moreover, the time-course study showed that the caerulein-induced increase in both 5HIAA and 5HT levels lasted even for 24 hours, and their levels tended to recover to the control values gradually. This time-dependent change was not found in the other monoamines and their metabolites. These results suggest a long-lasting action of caerulein on 5HT neurons in specific regions of rat brain.
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Riviere P, Bueno L. Influence of regimen and insulinemia on orexigenic effects of GRF1-44 in sheep. Physiol Behav 1987; 39:347-50. [PMID: 3106998 DOI: 10.1016/0031-9384(87)90233-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effects of intracerebroventricular (ICV) and intravenous (IV) administration of human GRF1-44 on feeding behavior were tested in hay- and concentrate-fed non lactating ewes. Administered ICV 5 min prior to hay disposal in 16 hr fasted ewes, GRF1-44 increased the first 3 hr and daily (8 hr) food intake by 25.3 and 24.5% respectively; this corresponded to a higher rate of ingestion during the first 3 hr. Similar effects on feeding behavior were observed after IV administration of a 10-times greater dose of GRF1-44 (1 microgram X kg-1), with daily hay consumption increasing from 1125 +/- 44 g (control) to 1407 +/- 91 g. In contrast, food intake of concentrates was significantly (p less than 0.05) higher only during the first hour of feeding and the daily food intake was unchanged. Both ICV (40 mU X kg-1) and IV (400 mU X kg-1) administrations of insulin did not affect feeding behavior per se, but suppressed the increased food intake of hay induced by IV GRF1-44. It is concluded that the orexigenic effects of GRF1-44 are probably centrally mediated and depend on regimen and digestive status. It is suggested that the insulin response to a meal of concentrates may be responsible for the early blockade of the orexigenic effects of GRF.
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Abstract
The importance of the central monoamines NE, DA and 5-HT in ingestive behavior has inevitably resulted in considerable effort being expended in attempting to implicate these monoamines in the mechanism of action of anorectic drugs. The statements that amphetamine-induced anorexia is unlikely to be due to central serotoninergic systems and that central noradrenergic and dopaminergic systems are not implicated in the appetite suppressant effect of fenfluramine are in all probability correct. However, to attribute the ability of drugs to decrease food intake unequivocally to a specific effect on central monoaminergic systems is almost certainly an oversimplification, due to the fact that other putative neurotransmitters, such as GABA and peptides, play a critical role in eating. This can be achieved either directly or by modulating the release of other transmitters. An added complication in attempting to correlate a specific neurochemical process to a behavioral effect, such as anorexia, is the complexity of the central actions of the drug. At best, a predominant but not an exclusive process can be identified. Perhaps the in-built constraint of attempting to correlate a specific neurochemical effect to the desired action of a drug is accountable for the absence of a second generation of centrally acting anorectic drugs. Dramatic progress has been made in elucidating the factors involved in ingestive behavior over the last 5-10 years. This information should, and must, provide the catalyst for more efficacious anorectic drugs because obesity represents one of the few major diseases for which adequate drug therapy does not exist.
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Myers RD, Swartzwelder HS, Peinado JM, Lee TF, Hepler JR, Denbow DM, Ferrer JM. CCK and other peptides modulate hypothalamic norepinephrine release in the rat: dependence on hunger or satiety. Brain Res Bull 1986; 17:583-97. [PMID: 3536002 DOI: 10.1016/0361-9230(86)90229-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The purpose of this investigation was to determine the functional relationship between putative satiety peptides and endogenous norepinephrine (NE) activity in the hypothalamus. Permanent guide cannulae for push-pull perfusion were implanted stereotaxically in Sprague-Dawley rats so as to rest above the medial or lateral hypothalamus (LH). Post-operatively, the animals were either satiated with food and water, both available ad lib, or fasted for 18-22 hr prior to an experiment. To perfuse a site in the LH, paraventricular (PVN) or ventromedial nucleus (VMN), a concentric 29-23 ga push-pull cannula system was lowered to a pre-determined site, in most cases after catecholamine stores had been pre-labeled with [3H]-NE. During control tests, an artificial CSF was perfused at a rate of 20-25 microliter/min for 5-8 min with a 5 min interval between each sample. The addition of cholecystokinin (CCK) in a concentration of 2.0-6.0 ng/microliter to the CSF perfused in PVN or VMN of the satiated rat enhanced the efflux of NE; however, in the fasted animal CCK often suppressed the catecholamine's release. Perfused in the LH, CCK exerted opposite effects, typically augmenting NE output when the rat was fasted but not affecting the amine's activity during the sated condition. Proglumide (1.2 micrograms/microliter) attenuated CCK's effect in releasing NE when the antagonist was perfused in the PVN of the satiated rat. Similar experiments in which neurotensin (NT) was perfused in the LH, PVN and VMN revealed virtually the same inverse effects on NE release in the fasted and satiated rat, which again were anatomically specific. Finally, insulin and 2-deoxy-D-glucose (2-DG) exerted similar state-dependent effects on the release of NE within LH and PVN. Overall, the results suggest that CCK or other neuroactive peptide could serve as a "neuromodulator" of the pre-synaptic release of NE within classical hypothalamic structures which are thought to underlie both hunger and satiety. The state-dependent nature of the peptides' activity on the noradrenergic feeding mechanism implies that these substances constitute a pivotal portion of the profile of factors which impinge functionally upon the hypothalamic neurons responsible for the feeding response and its cessation.
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Abstract
This paper is the eighth installment of our annual review of research involving the endogenous opiate peptides. It is restricted to the non-analgesic and behavioral studies of the opiate peptides published in 1985. The specific topics this year include stress, tolerance and dependence, eating, drinking and alcohol consumption, gastrointestinal and renal activity, mental illness, learning and memory, cardiovascular responses, respiration and thermoregulation, seizures and neurological disorders, activity, and some other selected topics.
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